Senator Mike Johanns will hit the exits after a single term in the upper chamber, his office announced yesterday.  The Nebraska Republican will bow out of a re-election bid despite having done well by all accounts in a first term.  Johanns reportedly has grown too frustrated with gridlock to fight for another six years:

Despite only serving one term, Johanns, 62, had begun to accrue seniority among an increasingly junior Senate Republican Conference, holding seats on prominent committees, including Banking and Agriculture. But after pushing for a major deficit-cutting deal in the last several years, the Republican has grown increasingly frustrated at Congress’s perpetual stalemate and its inability to resolve major national problems. Johanns informed his staff and Republican Gov. David Heineman of his decision Monday morning, sources said.

The early retirement decision caught Republican leaders by surprise — given that he had signaled for months he had planned to run again. But the early announcement — the fifth senator to do so this cycle — gives both sides a chance to reassess the landscape ahead of 2014.

The landscape, in this case, is very favorable to Republicans in a state that went for Mitt Romney by almost 22 points:

The retirement of Johanns — a former GOP governor of Nebraska and one-time secretary of agriculture — gives Democrats a shot at a seat they ordinarily would have dismissed, but Republicans remain favored to hold the seat in a state that is reliably Republican.

Don’t forget that Deb Fischer won her first Senate election in November with Obama at the top of the ticket, running against former Senator and war hero Bob Kerrey.  She beat Kerrey, who was seen as the Democrats’ best shot of holding Ben Nelson’s old seat, by sixteen points, as Kerrey outperformed Obama in the election.  After two more years of Obama and his turn to the left, Nebraskans probably won’t be in any better mood to elect Democrats to the Senate in 2014.

NPR’s Ken Rudin wonders whether the GOP fight against another Nebraska Republican might not have soured Johanns on a nearly sure-thing re-election bid:

No one has mentioned this — certainly Johanns has not — but I wonder if his steadfast support for Chuck Hagel, his fellow Nebraska Republican, to be the next secretary of defense was a factor in his decision. The GOP has, for the moment anyway, blocked Hagel’s nomination from reaching the Senate floor with a filibuster-like maneuver (known as the “filibuster”). Johanns was one of just two Republicans in the Senate who said he would vote for confirmation (the other being Thad Cochran of Mississippi). Was Johanns frustrated with his party, and did that play a role in him deciding he had had enough?

If so, it seems like an overreaction, since Hagel will almost certainly get confirmed next week, even if he shouldn’t.  I’d tend to believe it has more to do with the dysfunctional budget process that Johanns has had to endure for almost the entirety of his term in office, which is a lot more significant than the fight over Hagel and the rejection by his colleagues of the Defense appointee.  We’ll find out in the memoirs.

Rudin points out that the retirements are now at 5, with Democrats leading 3-2 — Lautenberg, Rockefeller, and Harkin, with Johanns and Chambliss for the GOP.  Two more potential retirements still await, one from each party: Cochran and Tim Johnson of South Dakota, plus however many more surprises might turn up.  Democrats will have more seats to defend in 2014 and (at the moment) one more open seat, but that was true in 2012, and the Republicans couldn’t take advantage with Obama at the top of the ticket.  Without Obama and after the aforementioned left turn in his second term, Democrats might have trouble holding the Senate — if Republicans can avoid stepping all over themselves.