Despite popularity, Tester narrowly trails Rehberg

Sen. Jon Tester is considerably more popular than his likely 2012 opponent, Rep. Denny Rehberg, yet still lags the Republican by a hair in his bid for a second term representing Montana. In fact, Tester is the most popular senator we've ever polled on who still trails in a re-election horserace.

Tester's 51-39 approval margin is essentially unchanged from when we last took a look at the state about a week after last November's election, when it was 50-40. And his deficit to Rehberg also has not budged. He was down 48-46 then, and 47-45 now. That is despite voters' views of Rehberg declining, from a 49-37 favorability rating to only a 44-45 approval rating. The main change there has come with independents, who make up almost a third of the state's voters. They saw him favorably, 46-37, last fall, but disapprove 35-54 now, almost the opposite of their 53-36 approval of Tester.

Yet in spite of a negative trend in Rehberg's public perception with swing voters and the fact that Tester is the second most popular Democratic senator from a McCain state after West Virginia's Joe Manchin, his head-to-head with Rehberg hasn't moved because of the persistent though not overwhelming red lean of the state (Republicans outnumber Democrats 39-31), and because Rehberg does a better job than Tester of translating approval into votes.

Tester's party approves of his job performance, 89-5, but 10% of them say they'd vote for Rehberg at this point, and 86% stay faithful. Rehberg actually improves on his standing with his own party. 13% of them disapprove of his performance, and only 74% approve, but he locks up their vote, 86-8. Tester does have a 51-36 lead with independents, helping to cut into the GOP ID advantage.

To win, Tester is obviously going to have to do some combination of continuing to grow his lead with independents (he was up 49-39 in November), rallying his party base, and cutting into Rehberg's strength across the aisle. Numbers-wise, the latter is the way to go, since Republicans are a 39% plurality, but practically, that is unlikely. So Tester will probably try to paint himself as a Schweitzer-like common-sense populist and Rehberg as an extremist. Unfortunately for him, Rehberg was one of only four House Republicans to vote against the Paul Ryan budget proposal, and that vote has yet to produce a challenge from the right.

Tester's senior colleague, Max Baucus, could have an even tougher fight on his hands in 2014 than Tester will next year. Baucus' approval numbers are up a bit from November, when 53% disapproved and only 38% approved. But his 40-50 figure now is not much better. He is less popular than Tester with Democrats, Republicans, and independents alike. The state's longest-serving senator beat a fringe GOP opponent by 46 points in 2008, but that performance will be impossible to top in a midterm, if the current 69-year-old even runs for a seventh term.

Full results here.