SurveyUSA: Talent Takes Back Lead

3 is the magic number.

Sen. Jim Talent has retaken the lead over Democratic challenger Claire McCaskill by three points, due in part, to a newly energized conservative base, according to a poll taken by SurveyUSA.

Sen. Jim Talent 48%
Claire McCaskill 45%
Undecided 5%

The poll was taken between October 21-23 of 630 likely voters, with a margin of error of +/- 4%.

It is a dramatic swing from a SurveyUSA poll taken two weeks ago that showed McCaskill ahead by 9 points. This is a significant 12-point swing towards Talent.

Here is the explanation:

Two things are simultaneously at work: In the 10/12 poll, 32% of Likely Voters identified themselves as Republican. Today, 38% do. Republicans appear newly energized in this contest, in part driven by the forces at work on Amendment 2, separate analysis to follow. Second, in the 10/12 poll, McCaskill led by 13 points among Independent voters. Today, Independents are tied at 41%. The number of "undecided" Independents has doubled since the 10/12 poll, and the number of Independents voting for Libertarian Frank Gilmour has doubled since the 10/12 poll. In the Ozark Region, Talent led by 6 on 10/12. Today Talent leads by 36, a 30-point swing to the Republican. In rural Central Missouri, McCaskill led by 16 on 10/12. Today, Talent leads by 8, a 24-point swing to the Republican. The St. Louis and Kansas City regions continue to favor McCaskill. There is other movement: Talent had trailed among whites, now leads. Talent had trailed among the youngest voters, now leads.

A 30-point swing in the Ozarks? That seems like a hell of a swing in just a couple of weeks. Is it possible one of these polls was poorly sampled?

The poll also shows the relationship between the U.S. Senate race and the constitutional amendment to protect stem cell research:

On 10/12, McCaskill led by 44 points among voters who were certain to vote "Yes" on Amendment 2. Today, McCaskill leads by 38 points among the "Certain Yes" voters. But: the size of the "Certain Yes" group has shrunk from 57% of Likely Voters on 10/12 to today 45%. On 10/12, Talent led by 68 points among voters who were certain to vote "No" on Amendment 2. Today, Talent leads by 56 points among the "Certain No" voters. But: the size of the "Certain No" group has grown from 27% of Likely Voters on 10/12 to today 36% of Likely Voters

Finally, there is this:

Last, an imponderable: On 10/21/06, the first day of the field period for this survey, McCaskill began airing a TV commercial that featured the actor Michael J Fox, who suffers from Parkinson's disease. There is no way to estimate, or even guess at, whether this advertisement had an impact on the numbers that SurveyUSA reports today. SurveyUSA will make note, however, that the interviews for a competing poll released today by Mason-Dixon, which show McCaskill ahead by 3 points, were completed on 10/19, before the Michael J Fox advertisement aired. It is unclear if the airing of the Fox ad is entirely coincidental to the movement observed here by SurveyUSA, or if there is some relationship. Many other factors were simultaneously at work in Missouri, including a tougher, more aggressive stance taken by Talent in his debate appearances with McCaskill, and advertisements taken out by Talent attacking McCaskill. Those factors acknowledged, Talent did better day-by-day in this survey, from Minus 1 on Saturday 10/21, to Plus 5 on Sunday 10/22, to Plus 7 on Monday 10/23. When the 3 days of interviewing are averaged, Talent is up 3 points, which are the results SurveyUSA presents here.