U.S. Sen. Tom Harkin cruised to re-election Tuesday, easily capturing a fifth six-year term over Republican challenger Christopher Reed.

Harkin, 68, a Democrat from Cumming, was well ahead in early returns in what was expected to be the largest margin of victory in his Senate career. The Associated Press projected his win shortly after the polls closed.

Harkin and his wife, Ruth, joined fellow Democrats at an election night party at the Hotel Fort Des Moines, where he thanked Iowans for again placing their trust in him. He had spent the final three days of the campaign barnstorming 16 Iowa cities with Gov. Chet Culver and other Democrats.