As he does, gun rights interests are mounting their own big political effort. “Gun owners are stirred up and there is plenty of talk already on the gun rights forums about getting out the vote in 2014,” said Dave Workman, senior editor of The Gun Mag, a gun rights publication.
Here’s a look at the biggest tossups:
– Alaska. Begich won his first term in 2008 with 48 percent of the vote against a weak incumbent. He could face Republican Joe Miller, who won the party’s 2012 Senate nomination with strong help from the conservative tea party movement.
– Arkansas. Pryor, the son of a former governor and senator, won his last term with no Republican opposition. But he’s running in a state trending Republican, where Obama got 36.9 percent of the 2012 vote. Political analyst Stuart Rothenberg has dubbed Pryor the most vulnerable Senate incumbent.
– Iowa. Rep. Bruce Braley is considered a strong Democratic candidate, and it’s unclear who the Republican challenger could be. Iowa’s a state where liberals and conservatives both have strong, active constituencies, making the results of a statewide race unpredictable.
–Louisiana. Landrieu is a veteran of tight, tough races in a state where gun rights are sacred. But nearly one-third of the voters are black, and if they turn out in big numbers, she’ll have an edge.
– Montana. Former Gov. Brian Schweitzer, a Democrat, is expected to be a leading contender for the seat of Senate Finance Committee Chairman Baucus, who on Tuesday announced he’s retiring.
North Carolina. Hagan beat an incumbent senator five years ago with 53 percent, a year when Obama narrowly won the state. She won’t have those coattails now, and the state voted heavily Republican in 2012. Her background check vote is likely to make her a favorite target of the gun rights crowd.
– South Dakota. Even if Johnson had run, he would have been vulnerable to popular former Gov. Mike Rounds or Rep. Kristi Noem. Republicans have thrived here lately, electing over the last three years a governor, an at-large congressman, a senator and a heavily Republican legislature.
– West Virginia. Long a Democratic stronghold, the state has been trending more Republican. Rep. Shelley Moore Capito, R-W.Va., is the favorite to take the seat, though she faces a primary challenge from the right.