Jon Tester (D) pulls into lead in Montana Senate race

Jon Tester Public Policy Polling (PDF). 4/26-29. Montana voters. MoE ±3.2% (5.4% for Democratic primary sample) (11/28-30/2011 in parentheses):

Jon Tester (D-inc): 48 (45)
Denny Rehberg (R): 43 (47)
Undecided: 9 (8)

The Montana Senate race is one of the key ones for Senate control in 2010. Elected in 2006 by only a few thousand votes in a red state, amidst a Dem wave year and against Conrad Burns, an unpopular, Abramoff-linked Republican opponent, re-election in 2012 was always going to be a tough row for Jon Tester to hoe. In fact, with Ben Nelson's retirement, he's probably the most vulnerable Senate Dem incumbent up in 2012 (Claire McCaskill being his only real competition for that title). And needless to say, any path for the Republicans to take control of the Senate has to go through picking up Montana.

Polling in this race has been, if nothing else, consistent. Public Policy Polling polled here three times in 2011, and each time they found Republican challenger Rep. Denny Rehberg leading by 2. (A few other pollsters have looked at the race, usually also finding a small Rehberg lead; in fact, it's been a year since anybody gave Tester a lead, in this case Mason-Dixon in March 2011.) However, PPP's newest look at the race breaks the pattern significantly: now they find Tester leading by 5.

There hasn't been a game-changing event in this race recently (unless you count the start of TV advertising, although I doubt that Jon Tester's first ad, a folksy spot which focused on how he brings his own beef to Washington with him from Montana, was worth a seven-point swing all on its own). The last poll was taken back in November, when the country's mood was a little more dismal; as economic improvement and the fallout from the Republican presidential primaries seemed to boost Barack Obama over the intervening months, so too may Tester have benefited.

The swing in independents (who make up 37% of the Montana electorate) seems to have made the difference since the last poll. Indies supported Tester by 5 points last time, but now give him a 12-point spread. In addition, Tester pushed his share of the Dem vote (who make up only 30% of the electorate) from 86% up to 90%, critical in a state where Democrats are outnumbered by Republicans.

Kim Gillan (D): 27
Steve Daines (R): 33
Undecided: 40

Franke Wilmer (D): 25
Steve Daines (R): 36
Undecided: 39

PPP also takes their first look at the state's at-large House seat, open for the first time in a decade with Rehberg's decision to go for the promotion. Given how little-known these candidates are, what we're seeing at this point is just the relative size of the two bases (and there are more straight-ticket GOP voters than Dem ones in Montana); the persuadables don't know anything about this race, and it won't get interesting until they do. For now, businessman and presumptive GOP nominee Steve Daines leads both Democratic state Sen. Kim Gillan and state Rep. Franke Willmer by solid but not insurmountable margins. Gillan leads the Democratic primary at 21, with Diane Smith at 13, Willmer at 11, Missoula city councilor Dave Strohmaier at 9, Sam Rankin at 4, Rob Stutz at 1, and 41 percent undecided.