Compared to some of his more high-profile colleagues, Sen. Mark Pryor isn’t well-known for his party-bucking ways. In fact, it wasn’t until three and a half years into his Senate tenure that the Arkansas Democrat began to show small signs that he could be a bit of a rebel.

But now that Democratic leaders are desperate for party loyalty in their showdown with the White House over the Iraq War, Pryor, who is up for re-election in 2008, is taking what most Democrats believe is a principled — rather than electoral — stand against setting a public timeline for withdrawal from Iraq.

“I don’t see myself as a Democratic war maverick,” Pryor said in an interview last week. “Really, the way I see it is, I’m here to represent the people of Arkansas, not the Democratic Party.”

He added, “More often than not I line up with the Democrats, but it depends on the issue.”

And the issue this Congress couldn’t be more divisive or hard-fought.

In defiance of Senate Majority Leader Harry Reid (D-Nev.) and other party leaders, Pryor was one of three Members of the Democratic Caucus who voted against a Reid-driven resolution to limit the U.S. mission in Iraq and require the president to begin redeploying troops out of the country within four months, with the goal of ending combat missions in Iraq by March 31, 2008. Reid lost that March 15 vote 48-50.

Two weeks later, even as Nebraska Democratic Sen. Ben Nelson was changing his vote to conform to party leaders, Pryor refused to budge on a similar vote on the emergency supplemental war spending bill, despite intense lobbying from Reid and others.

“I knew that my Democratic colleagues wanted me to vote the other way. They wanted me to vote their way,” Pryor said. “For the most part, when I explained my position and gave them my rationale, they understood where I was coming from. … So, I didn’t feel pressure, in the sense that you sometimes feel on other matters.”

Even without Pryor’s vote, Reid was able to keep the timeline for withdrawal in the war spending bill with the support of two Republicans — Sens. Chuck Hagel (Neb.) and Gordon Smith (Ore.).

Unlike his friend Sen. Joe Lieberman (ID-Conn.), who lost a primary challenge last year because of his stalwart defense of the Iraq War, Pryor favors setting a date for withdrawal. He just wants that date to remain classified so that terrorists in Iraq would not be able to plan around such a timetable.

“My concern is for the troops, and to me it’s a military decision. That’s why I think [a timetable for withdrawal] should be classified, like most military decisions are,” he said.

The son of a popular former Arkansas Senator, Pryor likely could have voted with fellow Democrats and not seen much backlash in his home state, several Democratic sources said.

“There is no one who is a more popular politician in Arkansas than Mark Pryor,” said Rep. Mike Ross (D-Ark.).

Ross said Arkansas voters primarily are focused on the military aspect of the war — such as whether their home-state soldiers are deployed — than on the latest political winds in Washington, D.C. Pryor’s voting record reflects that, Ross said.

“I don’t think it was a political vote for him,” Ross said. “It was a vote of conviction. He’s voting from his heart.”

As such, Ross said he has no worries that Pryor’s independence will have any effect on his success in 2008.

“I don’t think his vote helps him or hurts him,” he added.

Sen. Blanche Lincoln (D-Ark.) split with Pryor on the Iraq vote, saying, “I feel like the people of Arkansas are in a place that they’re anxious for us to change the direction in Iraq.” She said she did not discuss her vote with Pryor beforehand but said he is “a very thoughtful legislator.”

But others contend that Pryor’s re-election campaign certainly was a factor in his decisions to establish himself as a swing vote in the Senate.

“It’s all a state analysis. He thinks he needs it. Other people disagree,” said one knowledgeable Senate Democratic aide.

Pryor — similar to Lieberman — could face a Democratic primary challenge from Arkansas Lt. Gov. Bill Halter, who has refused in recent months to rule out such a bid. But unlike Lieberman, who won re-election as an Independent, Pryor may face a tough Republican challenger in former Gov. Mike Huckabee, who currently is running for president but could be persuaded to enter the Senate race if his White House bid falters.

Sen. Ken Salazar (D-Colo.), a political and personal ally of Pryor’s, voted with party leaders on both Iraq votes but said re-election concerns have played a big part in how people have been voting.

“I think, for both Democrats and Republicans, this is the issue of our time,” Salazar said. “So I think everybody who’s up in 2008, they are carefully considering and analyzing their vote.”

Pryor said he is nonplussed about the media’s focus on his decision to defy Senate Democratic leaders as well as suggestions that he was making a political calculation in anticipation of his 2008 campaign.

“It’s funny. The press really sees this through the frame of a party vote, and I think that’s unfortunate,” he said. He added, “I don’t see it as a political issue. If anything, I would say that that’s one of the problems here in Washington. People treat Iraq as a political issue. … Both sides are playing politics with it.”

Pryor first showed a willingness to go against the party grain in May 2005 when he joined the “Gang of 14” in a bid to prevent a showdown between Reid and former Majority Leader Bill Frist (R-Tenn.) over the ability of the minority to filibuster judicial nominees. Frist had been threatening to invoke the “nuclear” option in which he would get a ruling on the Senate floor that filibustering judges was unconstitutional. The Gang of 14 — seven Republicans and seven Democrats — banded together to oppose the move and brokered a compromise on nominees.

But even though he joined the group, Pryor remained a loyal party soldier, keeping Reid abreast of the Gang of 14’s deliberations.

Pryor, however, said his splits with fellow Democrats should come as no surprise to anyone, given that he told Sen. Tom Daschle (D-S.D.), who served as both Majority and Minority Leader while in the Senate, early on that he would be unpredictable.

“I said, ‘I want you to know that I’m not always going to be with you,’” Pryor said of his comments to Daschle in 2002. “I want to do my best for the people of Arkansas … and that means sometimes I break with the party.”

Erin P. Billings contributed to this report.