Iowa Sen. Tom Harkin says he will not seek re-election in 2014.
The 73-year-old Harkin tells The Associated Press in an interview, "It's just time to step aside," because by the time he would finish a sixth term, he would be 81.
Harkin said it would also allow a new generation of Democrats to seek higher office. The announcement comes as a surprise, considering he had $2.7 million in his campaign war chest and was planning a fundraiser next month.
Harkin played a lead role in urging the Senate's more liberal members to back the 2010 health care bill.
No Iowa Republicans have taken formal steps toward seeking the seat. Harkin's decision eases the burden on the GOP, who have to gain six seats to win the majority.