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.

Tom Harkin’s indelible impression is apparent across Iowa and America. Just ask anyone in a wheelchair. Or anyone fueling up a vehicle. Or anyone planting American crops or eating American food.

Harkin’s enduring impressions are evident in the stronger American farm economy, higher grain prices and a diminished reliance on production subsidies. His work makes it easier for disabled people to live, learn and earn, which also strengthen’s our country and economy.

His seniority gives Iowans the most influential voice in agriculture since Harkin chairs the Senate Agriculture Committee.

His seniority gives Iowans a front-row voice in health care reform since he’s a senior member on the Health, Education, Labor and Pensions Committee.

Harkin owes that influence to Iowans, who have returned him to the Senate for four terms.

We heartily endorse him for a fifth.

Democrat Tom Harkin would have our endorsement for a fifth term in the U.S. Senate if for no other reason than for how he was able to keep his cool after the insultingly bizarre pronouncements of his Republican opponent, Christopher Reed of Marion, in Thursday’s televised debate. But Harkin has our endorsement -as he did in 1984, 1990 and 1996 – because he has proven to be an effective lawmaker who looks out for Iowa’s best interests even as he plays a powerful role on the national stage.

Six years ago, we did decide to endorse Harkin’s Republican opponent, then Rep. Greg Ganske of Des Moines. We did so knowing the risk involved with replacing the power of a senior senator with the sometimes lone vote of a freshman. But we were gambling on the type of senator we thought Ganske could be in the future.

This year, we’re downright fearful of the type of senator that Reed could become.

For us, U.S. Sen. Tom Harkin always has been something of an enigma.

We don’t support many of his viewpoints, especially those on the far left. Yet, we can’t quarrel with the senator’s commitment to projects that can and do make a difference in Iowa. Whether by finding federal dollars to help establish community health centers, investing in communities and businesses, helping fix schools in need of repair or acquiring funds for local law enforcement, Harkin looks out for the folks back home. Sioux Cityans can thank Harkin for his efforts on behalf of the Perry Creek flood control project.

Harkin, a Democrat, and fellow Iowa Republican Sen. Charles Grassley are two of the strongest voices in their chamber. Having two such well-connected, high-ranking and influential senators clearly is good for this state.

In the end, Harkin’s experience and commitment to Iowa makes him a better candidate than Republican challenger Chris Reed, who has never run for or held public office. That’s why today the Journal endorses Harkin’s bid to retain his Senate seat.

The conundrum in national politics is that you have to be in office for a long time to win coveted leadership positions and chair committees, where you can really direct the national agenda.

But the more time spent among the Washington elite, the more constituents back home feel a sense of disconnect with their elected representatives. It’s a legitimate concern.

Tom Harkin, however, has deftly been able to remain a down-home Iowan while spending more than three decades shuttling back and forth to Washington. Iowans should give him another six years to work on their behalf in the United States Senate.

Harkin of Cumming is a lock to win his fifth six-year-term over political novice Christopher Reed, a Solon businessman who has never held any public office.