Sen. Tom Harkin, D-Iowa, won't seek reelection

Sen. Tom Harkin, D-Iowa, a five-term veteran of the Senate, told the Associated Press in an interview that he will not seek a sixth term in 2014, saying, "It's just time to step aside."

Harkin, 73, would be 81 years old by the end of a sixth term, a factor that weighed on his decision to not mount another reelection bid.

He also said the move would enable a new generation of Iowa Democrats to seek higher office.

Harkin's decision comes as a surprise, given his $2.7 million campaign war chest and a fundraiser scheduled for next month. No Republicans had stepped forward to challenge Harkin, though the prospect of an open seat may entice more candidates to join the fray.

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Harkin's retirement follows the lead of Sens. Saxby Chambliss, R-Ga., and Jay Rockefeller, D-W.V., who have said they will not seek reelection in 2014.