Another poll has been released today in the race between Sen. Patty Murray (D-WA) and real estate tycoon-turned-perennial-candidate Dino Rossi (R). The FOX News poll taken on 30 October on 1,000 likely Washington voters (for a 3% MOE) has Patty Murray leading Rossi 49% to 47%.

That’s very interesting, because earlier today, I reported on a Public Policy Polling poll that had Rossi in the lead by +2%. Both were robopolls.

My usual Monte Carlo analysis of this poll has Murray wining 671,871 times, whereas Rossi wins 319,994 times. In other words, this poll alone gives Murray a 67.7% probability of winning to Rossi’s 32.3% chance.

Combining the last seven polls—all taken over the past two weeks—gives a total of 6,371 “votes” to work with. Of these, Murray received 3,073 (48.2%) of “votes” and Rossi received 3,052 (47.9%). The Monte Carlo analysis has Murray winning 568,596 simulated elections to Rossi’s 427,966 wins. That is, the polls support a Murray victory by 57.1% and a Rossi victory by 42.9%.

The result is close! Neither analysis presented here can be considered outside the margin of error. Here is, what I believe is, the final graph for this race: the last couple of months of polling results:

Make of it what you will. The polls say it is a tie or a very small Murray victory. So what do I think will really happen tomorrow? First, let me state that I obviously want Murray to win. Even so, in my professional life, I am a scientist, and evidence is exceedingly important to me, even if it goes against my desires or pet theories. So here goes….

As I outlined at the end of this post there is a discrepancy between live interview polls and robopolls in the Washington Senate race that has also been seen nationally. I offered an explanation (i.e. a theory) as to why the discrepancy exists. It all leads me to believe that robopolls are systematically underestimating Murray’s performance in this race. If the theory is correct, I expect Murray to come away with about a +5% advantage over Rossi after all the votes are counted. But I concede that tomorrow night, reality will confront theory.

Reality always wins.

Public Policy Polling has released their final poll of the election season in the Washington Senatorial race. The poll, taken from 29-31 October on as sample of 2,055 likely voters (giving a 2% MOE) has Sen. Patty Murray trailing real estate peddler Dino Rossi 48% to 50%.

While this is only the fourth of twenty polls taken over two months that has Rossi ahead, Rossi has led in two of the past four polls, and Murray has only led in one of them.

A Monte Carlo analysis of the PPP poll shows Murray winning 256,364 simulated elections to Rossi’s 738,506 wins. The poll provides evidence that Murray would win with a 25.8% probability to Rossi’s 74.2% probability. Since Rossi’s winning probability is under 95%, the result is, technically, a statistical tie. But don’t be fooled…Rossi has an advantage by this poll, as is clear in the distribution of simulated election outcomes:

A more complete picture of the election outcome comes by examining all polls taken over the past two weeks. There have been six polls conducted since 17 October until 31 October, and it includes all polls taken since ballots were mailed to most Washington state voters. The metapoll includes 5,371 responses, of which 2,583 are for Murray and 2,582 are for Rossi.

No kidding! They are literally tied as they can be, given the odd number of respondents who chose to “vote.” Can you say “recount!” and “paging Judge Bridges”? I think it is fair to say that this race has seen movement over the past month that has favored Rossi in dissolving Murray’s clear lead.

I’ll end this post with the raw polling picture over the past two months. In a race so close, different people will squint at this graph, view it through different ideological or partisan filters, dump polls they don’t “like”, and come to different conclusions. In fact, this race is, based on any individual poll or based on every poll taken in the past two weeks, utterly indistinguishable from a tie.

Of all people, Washingtonians should understand the importance of getting out the vote. You may recall a very close state-wide race in 2004 that was won by a 129 vote margin (later judicially adjusted to 133). The loser of that race was Republican Dino Rossi, who is now challenging Sen. Patty Murray for the Senate seat she now holds.

Let’s not have a repeat of that…and you can help.

MoveOn.org is hosting GOTV calling parties to help re-elect Sen. Patty Muray and elect Suzan DelBene. They are looking for volunteers to spend an hour or two doing some good old fashioned voter outreach.

They are particularly interested in volunteers to make calls out of their Bellevue office at three times: Sunday at Noon, Sunday at 4:00 pm, and Monday at 1:00 pm. If you have an hour to spare during these (or even other) times, consider helping out. Start by giving them a call at 425-450-1054.

A new Marist poll has been released in the race between Sen. Patty Murray (D-WA) and real estate wheeler-dealer Dino Rossi (R).

The poll of 638 likely voters (4.0% MOE) taken from 26-28 October has Murray leading Rossi 49% to 48%. Marist polls use live interviews and include a sub-sample of cell phone interviews. As we saw with the Marist poll from two weeks ago that had Murray up by +1%, the current poll is evidence against the otherwise strong trend of live-interview polls showing a modest (or better) lead for Murray.

I ran a Monte Carlo analysis that simulated a million elections using the observed preferences and sample size percentages observed in the new Marist poll. Murray won 567,112 elections and Rossi won 422,059 times. The poll (by itself) offers evidence that Murray would win with an election held over the past two weeks with a probability of 57.3%. Rossi would have a 42.7% probability of winning. Clearly, this result is a statistical tie, even if Murray’s odds are a bit better than Rossi’s.

With today’s poll, we have now had seven polls released that cover the past two weeks. Murray has led in five of the polls, Rossi has led in one, and one was a tie. A combined analysis of all seven polls provides a way to use all the recent evidence to assess this race. The resulting meta-poll had a total of 5,778 “votes” of which 2,797 go to Murray (48.4%) and 2,712 go to Rossi (46.9%). An additional 269 (4.7%) “votes” went to neither candidate.

The Monte Carlo analysis gives Murray 789,523 wins to Rossi’s 207,597 times. Thus these seven polls provide evidence that Murray would win an election held over the past two weeks with a probability of 79.2%. Rossi would win with a 20.8% probability.

With only three days to go until the Big Poll is tallied, it is worth a few minutes examining the recent trend in this race. Here is the collection of polls in September and October (I’ve excluded polls released by a candidate or party):

The very recent polling suggests a tightening race. Even so, Rossi has only led in three of 19 polls over the past two months, and all three were conducted by Rasmussen (and Murray has led in two other Rasmussen polls). Beyond that, Murray has led in all other polls conducted by seven other pollsters except for one of three SurveyUSA polls giving a tie.

The bottom line is that Murray looks like she will win this one, but there are some uncertainties that may be distorting the map between polling and actual voting. My hunch is that the uncertainties don’t help Rossi’s chances much and some favor Murray:

• Voter “turnout.” There really isn’t “turnout” in Washington, which has a very high proportion votes cast by mail-in ballots. Voter motivation should be less of an issue in this race than it will be in other states. You may have heard media reports about how a rainy day across the country on Tuesday will negatively affect Democratic candidates. While that may be true in states with poll voting, rain in Washington state can potentially give Democrats a boost by simply keeping inattentive voters in closer proximity to their unspent ballots.
• The “cell phone problem.” There wasn’t much evidence that this problem biased polls in 2008, but there is some more recent evidence to suggest it can now. Some pollsters, like Marist, include a cell phone sub-sample, but it is hard to do. If the phenomenon is real, Murray will do better than many polls suggest.
• The robopoll—live interview difference. I’ve been discussing this for weeks after Stuart Elway first raised it. The phenomena is observed nationally as well as in this race. Here, I suspect it will result in a 3%-4% boost for Murray over the robopolls, but nobody really knows what is causing the phenomenon. We’ll find out soon.

(And there is more good media stuff from the past week in politics at Hominid Views.)

As I mentioned here and here, we have been treated to two new polls today in the race between Sen. Patty Murray (D) and Dino Rossi (R).

A SurveyUSA was a robopoll taken on 678 likely voters (3.8 MOE) from 24-27 October and has Rossi and Murray tied up at 47% each. The KCTS/KPLU/Washington Poll poll used live interviews of 500 registered voters (4.3 MOE) taken from 18-28 October, and has Murray leading 49% to 45%.

In some sense, both of these polls are older than yesterday’s Rasmussen robopoll of 750 likely voters (4.0 MOE) taken completely on the 26th of October that has Rossi up +1% (48% to 47%). Therefore, the only reasonable thing to do is combine all three polls into one meta-poll and do a Monte Carlo analysis.

The combined 1,928 “votes” are split 916 for Murray (47.5%), 904 for Rossi (46.9%) and 108 (5.6%) for neither candidate. From a million simulated elections at these proportions and sizes, we learn that Murray wins 579,294 times and Rossi wins 414,495 times. In sum, these three most recent polls support a Murray victory with a 58.3% probability and a Rossi win with a 41.7% probability. This is very close to a tie (statistically, it is a tie), but Murray has a slight edge.

My usual near-election practice is to analyze all polls taken in the past two weeks. There are six such polls:

	Start	End			%	%	%
Poll	date	date	Size	MOE	Murray	Rossi	Diff
Rasmussen	26-Oct	26-Oct	750	4.0	47	48	R+1
SurveyUSA	24-Oct	27-Oct	678	3.8	47	47	0
WA Poll	18-Oct	28-Oct	500	4.3	49	45	D+4
Rasmussen	17-Oct	17-Oct	750	4.0	49	46	D+3
Marist	14-Oct	17-Oct	589	4.0	48	47	D+1
PPP	14-Oct	16-Oct	1873	2.3	49	47	D+2

The resulting meta-poll has a total of 5,140 “votes,” of which 2,484 go to Murray (48.3%), 2,406 go to Rossi (46.8%), and 250 go away. From a million simulated elections, Murray wins 785,190 times and Rossi wins 211,969 times. Thus, from the evidence found in polls taken over the past two weeks, we find that Murray has a 78.7% probability of winning and Rossi has a 21.3% probability of winning.

Statistically, the race is a tie because the probability of winning is under 95%, but the odds do favor Murray a little bit.

King 5 is reporting on a new SurveyUSA poll today in the race between Sen. Patty Murray (D) and perennial candidate Dino Rossi (R).

The poll has the race tied up at 47%. This is a robopoll of 678 likely voters with a margin of error of 3.8%. More analysis to come….

This morning KPLU reported on a new poll from KCTS/KPLU/Washington Poll in the race between Sen. Patty Murray (D) and real estate opportunist Dino Rossi (R). The poll has results presented in a couple of ways.

Among registered voters Murray leads Rossi 49% to 45%. However when a likely voter screen is used, Murray leads Rossi 51% to 45%. The survey was done using live interviews and has a margin of error of 4.0%. Full details on the poll will be available around noon. I’ll do a more in-depth analysis of the poll (and possibly another poll) later today.

We have fallen into a relatively dry spell for polling in the race between Sen. Patty Murray (D-WA) and real estate salesman Dino Rossi (R). Rasmussen has now released their latest Washington state poll showing Rossi leading Murray 48% to 47%. The poll of 750 likely voters was taken on Tuesday and has a margin of error of 4%.

This poll breaks Murray’s streak of eight consecutive polls with the lead. Before today’s release, the most recently taken poll was also by Rasmussen (17th Oct), and showed Murray with a +3% lead over Rossi (49% to 46%).

Using my usual Monte Carlo analysis employing 1,000,000 simulated elections, we find from the newest Rasmussen poll that Murray wins 415,950 elections to Rossi’s 573,763 wins. Thus, evidence from this poll alone suggests that, if the election had been held last Tuesday, Rossi would have a 58% probability of beating Murray to Murray’s 42% probability of beating Rossi. Given that the winning probability is under 95%, a statistician would tell us that the results suggest a statistical tie. Here is the distribution of simulated election outcomes:

A more comprehensive picture of the election emerges by combining all polls from the past two weeks. Besides the two Rasmussen polls already mentioned, we include the Marist poll taken from 14-17 October on 589 likely voters, giving Murray a +1% lead and a Public Policy Polling poll taken from 14-16 October on 1,873 likely voters and gave Murray a +2% lead. (Other polls in this race started the survey prior to the 14th of October so aren’t included.)

The combined meta-poll has 3,962 “votes” of which 1,920 go to Murray (48.5%), 1,862 go to Rossi (47.0%), and 180 (4.5%) just go away. In the Monte Carlo analysis, Murray wins 746,418 times and Rossi wins 249,788 times. In other words, the four polls suggest that Murray would win an election held over the past two weeks with a probability of 74.9%, and Rossi would win with a probability of 25.1%.

This collection of four recent polls gives the appearance that the race has tightened up a bit (compare this to the 98% win probability for Murray from pooled polls early last week). Keep in mind, however, that three of the four most recent polls are robopolls. As I discussed previously, there is a strong trend of robopolls showing Murray under performing relative to live-interview polls. Perhaps we will get a live-interview poll tomorrow….

It’s the Tuesday before the election. And that make for an excellent excuse to enjoy an evening of politics under the influence. Please join us at the Seattle chapter of Drinking Liberally at the Montlake Ale House, 2307 24th Avenue E. beginning at about 8:00 pm. Some of us will be there early for dinner.

Not in Seattle? There is a good chance you live near one of the 250 other chapters of Drinking Liberally.

On my way home this evening, I came across a pick-up truck parked on the street in Redmond, towing this trailer:

Without even thinking about, I started glancing around for evidence of a Dino Rossi campaign event….

(And there are almost 50 more links to media clips from the past week in politics at Hominid Views.)

This poll from Marist makes eight consecutive polls in which Sen. Patty Murray (D-WA) has the lead over Dino Rossi (R), even if her 48% to 47% lead is smallish.

I do a more detailed analysis of the poll, and an analysis using all nine October polls, at Hominid Views.

Man, after all this number crunching and writing…I needs me a drink!

It’s Tuesday following the ballot drop…making it a great opportunity to enjoy and evening of politics under the influence. Please join us at the Seattle chapter of Drinking Liberally at the Montlake Ale House, 2307 24th Avenue E. beginning at about 8:00 pm. Stop by earlier for dinner.

Not in Seattle? There is a good chance you live near one of the 249 other chapters of Drinking Liberally.