CUMMING, Iowa – U.S. Sen. Tom Harkin said Saturday he will not seek a sixth term in 2014, a decision that eases some of the burden the national Republican Party faces in retaking the Senate.

Harkin, chairman of an influential Senate committee, announced his decision during an interview with The Associated Press.

The 73-year-old cited his age — he would be 81 at the end of a sixth term — as a factor in the decision, saying it was time to pass the torch he has held for nearly 30 years, freeing a new generation of Iowa Democrats to seek higher office.

Harkin, first elected in 1984, ranks seventh in seniority and fourth among majority Democrats. He is chairman of the Health, Education, Labor and Pensions Committee, and chairman of the largest appropriations subcommittee.

Harkin has long aligned with the Senate’s more liberal members, and his signature legislative accomplishment is the 1990 Americans with Disabilities Act. He also served as a key salesman of President Obama’s health care overhaul to the wary left.

“I’m not saying that giving this up and walking away is easy. It’s very tough,” Harkin said at his rural Iowa home south of Des Moines. “But I’m not quitting today. I’m not passing the torch sitting down.”