No one has made life on the campaign trail more difficult for several of the frontrunning candidates for the Democratic presidential nomination than US Sen. Tom Harkin, D-Iowa.

Last October, Harkin joined Massachusetts Senator John Kerry, North Carolina Senator John Edwards, Connecticut Senator Joseph Lieberman and Missouri Representative Richard Gephardt in voting for the resolution that authorized President Bush to take military action against Iraq. But, last week, Harkin admitted that he has been wrong to believe the Bush Administration was serious about exploring diplomatic alternatives to war.

If Congress were to vote again, Harkin said, he would oppose the resolution. “I’m not going to be fooled twice,” the Iowan told hometown media in Des Moines. “As I look back it sure looks like the administration was never serious about resolving the situation peacefully,” said Harkin, who complained that Bush has acted “like the cowboy who rode out of Texas, all guns blazing.”

One of a growing number of Congressional Democrats who voted for the October resolution but who now are critical of the president’s failure to respect language that instructed the Administration to pursue diplomatic solutions, Harkin said, “In my adult life, with the exception of Vietnam, this has been the biggest failure of diplomacy I’ve seen.”

Harkin’s vote in favor of the October resolution deeply disappointed many Democrats in Iowa, where antiwar sentiment always runs high. And Harkin never suggested that he was overly happy with his vote; indeed, when he delivered the eulogy at Paul Wellstone’s memorial service last fall, Harkin praised the late Minnesota senator for having the courage to vote against the resolution.

But, even if Harkin was there uncomfortably, having Iowa’s most prominent national Democrat in the pro-resolution camp provided cover for Democratic presidential contenders such as Kerry, Edwards, Lieberman and, above all, Gephardt, who helped organize support for the use-of-force resolution when he served as House Minority Leader. For presidential candidates who backed the resolution, it was a relief to be able to respond to questions about a possible war by saying, “Like Tom Harkin…”

Now, they are no longer “like Harkin.” The Iowan says he did not mean to stir up trouble for the contenders for his party’s 2004 nomination. But Harkin, himself a former presidential candidate, is too sly a political player not to have known that his statement would stir the political pot. And so it did. In fact, when several of the Democratic candidates arrived in Iowa after Harkin had revealed his new stance, the candidates found that the pot was boiling. In a state where even Republicans — like Iowa City-area Congressman Jim Leach — have taken antiwar stances, the sentiments among Democratic activists tend to echo those of Polk County party leader Barbara Boatwright, who says, “I’d like to hear something stronger from Congress. I wish we’d have an outcry and protest from Democratic members of Congress.”

That was certainly the message Gephardt got when he arrived in Sioux City over the weekend to talk with Democratic activists whose support he will need in next January’s first-in-the-nation Iowa caucuses. The man who won the state’s Democratic presidential caucuses in 1988 took a battering from people like Western Iowa Tech Community College job training director Chris Hansen. “Congress has completely addicated its duty,” Hansen told Gephardt at a gathering of Woodbury County Truman Club members. “You’ve given up the final check and balance on this thing.”

Gephardt made a determined effort to steer the conversation toward domestic issues — such as education and health care — chosen to illustrate areas of agreement with the roughly 40 Democrats who had gathered to hear him. But it was to no avail. “If we’re going to go to war, shouldn’t Congress fulfill its constitutional duty and declare that war?” inquired Tom Whitmore, a veteran Democratic activist in the Sioux City area.

Gephardt, who said he would “stand behind my vote” on the October resolution, rejected talk about the need for a new vote by Congress. “If you’re saying you want to pass a resolution that says (the US) can’t do anything if we can’t get the whole UN wound up behind us, then you’re really turning decision-making on a very important security matter over to the United Nations. I don’t want to do that.”

Gephardt’s unwavering stance puts him in the camp of Lieberman, who pretty much parrots the Bush line on Iraq, and Edwards, who apologetically tells Iowa Democrats that his position is a matter of “conscience” and then struggles to shift the discussion to domestic issues. On the other side are two candidates who voted against the October resolution, House Progressive Caucus chair Dennis Kucinich, D-Ohio, and former Senate Intelligence Committee chair Bob Graham, D-Florida, and three candidates sharpyl critical of war, civil rights activist Al Sharpton, former US Sen. Carol Moseley Braun, and former Vermont Governor Howard Dean.

In the middle, and thus in the most difficult position following Harkin’s shift, is Kerry. When the Massachusetts senator arrived in Iowa Sunday for a series of campaign appearances, he was grilled on his views on Bush’s rush to war. Asked directly by the Des Moines Register, Kerry was reported to have “stopped short” of saying that he too regretted his vote last October. “What I do regret is that this Administration has not lived up to the standards of diplomacy set forth in the resolution,” said the man who is seen by many Democrats as the frontrunner for the party’s presidential nod. “The president’s diplomacy has been completely lacking.”

Aside from his murky stance on the question of whether his vote for the “use of force” resolution was a good one, Kerry’s comments on Bush sound similar to those of the candidate who most frequently criticizes Kerry for backing the resolution: Dean. In Des Moines, Kerry was particularly aggressive, arguing that, “The greatest position of strength is by exercising the best judgement in the pursuit of diplomacy, not in some trumped-up, so-called coalition of the bribed, the coerced, the bought and the extorted, but in a genuine coalition.”

That also sounds a lot like Harkin, save for the Iowa senator’s acknowledgement that Congress was wrong to give up so much authority to Bush. Harkin is a smart politician, who knows his state well. Indeed, as Woodbury County Democratic Party chair Al Sturgeon explained after the Sioux City session with Gephardt, “If I had a nickel for every time someone told me Congress wrote Bush a blank check, the Woodbury County Democrats would be in good shape.”