Rep. Tom Tancredo (R-Colo.) arrived on Capitol Hill while Bill Clinton was still president. But it wasn’t until George W. Bush took over that the lawmaker found his nemesis.

Tancredo’s hard line on immigration reform has transformed the third-term lawmaker from loyal Republican soldier into the bête noire of the Bush White House. But the schism is about more than a disagreement on policy; it’s also about the way Tancredo has chosen to do battle — as a lone, ever-present gadfly buzzing from talk-radio show to editorial board to cable news program, predicting peril if President Bush gets his way.

“The president has done more for my name ID than I could have done in a lifetime,” Tancredo said last week, after Bush laid out new proposals for contending with the country’s illegal immigrant population.

This assessment was not exactly accurate. By the time Tancredo spoke with Roll Call on Friday, the lawmaker had already made the rounds among dozens of media outlets. The fact is, Tancredo’s high profile is, as much as anything else, the result of his essentially unique willingness to stand up to the White House in public.

Even some who, like Tancredo, advocate tighter immigration controls express mild disbelief at his pluck.

“Anyone who takes on this issue has got to be courageous — you’ve got to care more about the issue than about your political status,” said Rosemary Jenks, a close Tancredo ally in the immigration reform movement.

It’s not as if no one in Congress agrees with Tancredo’s views on immigration policy. The Congressional Immigration Reform Caucus, which he chairs, has grown from 16 members to 71 in the two years since the Sept. 11 terrorist attacks. The entire group basically shares the view that the U.S. government must do more to restrict immigration — even legal immigration.

Nevertheless, Tancredo is now indisputably the face and name of the movement. He’s even become something of a foil on the issue of immigration for the president. Tancredo’s own Web site quotes Bush as saying, “I fully do not support Congressman Tancredo’s bill against H1B [visas].”

Tancredo “tells me that so many of his colleagues — even Democrats — come up and say, ‘Thank God you’re here to take the heat on this,’” said Steven Camarota, the research director at the Center for Immigration Studies, which is also allied with Tancredo. “Everybody lets him do the heavy lifting on this thing.”

Tancredo casts his relationship with the White House as one of unrequited admiration; he’s a political ally cut loose by a basic disagreement on a key area of policy. Communication simply doesn’t exist — at least not since that indelible moment two years ago, when presidential adviser Karl Rove told Tancredo to “never [again] darken the doorstep of the White House.”

Since then, Tancredo has had to look over his shoulder. Every so often rumors begin to surface that the White House is looking for someone to challenge the Colorado lawmaker in a primary.

Tancredo is not inclined to believe the whispers — he thinks it would be too great a political risk for the White House. But then weird things occur, like the time just before last session’s adjournment when Rep. Pat Toomey (R-Pa.) came to ask him about his problems with the White House.

Toomey, who is challenging Sen. Arlen Specter from the right in Pennsylvania’s GOP primary, told Tancredo that his name popped up during one of the debates back home. In explaining why the White House was backing Specter, Toomey suggested the president’s policy is to always back the incumbent — to which Specter quickly responded that the characterization was false: The White House was looking for someone to challenge Tancredo in Colorado.

“I don’t know where Arlen Specter got that information,” Tancredo said.

At least publicly, the White House maintains an open-door policy toward Members of Congress. “Everyone’s welcome at the White House, is my understanding,” presidential spokesman Trent Duffy said.

Duffy noted that all Members are sent invitations to the White House’s holiday party — even the Democrats are on that list.

Camarota suggested that Tancredo has had a substantial impact on the unfolding immigration debate, even if he has not been given a seat at the table. Camarota reckoned that Tancredo’s aggressiveness and ability to get his message out through conservative media outlets probably was part of the reason that Bush’s immigration plan did not include anything about green cards.

The roots of Tancredo’s immigration crusade were planted about 30 years ago, when, as a civics teacher at a junior high school the future lawmaker came into contact with bilingual education. He soon ran for the state Legislature, where for each of six years he introduced legislation to strip the state program’s funding.

Tancredo eventually started a public policy think tank called the Independence Institute. It was in this capacity that he commissioned a report on the impact of immigration on Colorado — “Compassion vs. Compulsion” — and arrived at his views on the subject.

Tancredo’s subsequent immigration efforts led him to launch a speaking tour in the state with former Colorado Gov. Richard Lamm, a Democrat who ran for the Reform Party’s presidential nomination in 1996. But when he began exploring a run for Congress, he quickly learned that immigration was an issue that lawmakers would generally prefer not to discuss.

Then-House Majority Leader Dick Armey (R-Texas), whom Tancredo met on an exploratory trip to Washington, tried to persuade him to apply his energies elsewhere. Tancredo recalled that Rep. Lamar Smith (R-Texas), who had been the point man on immigration policy inside the Republican Conference, told him, “If you get here [the issue is] all yours.”

Tancredo said it is logical that lawmakers would feel skittish about the immigration question.

“You are immediately conjuring up the epithets that may be used. Epithets like ‘racist’ and ‘xenophobe.’ No one like that,” Tancredo said. “It’s an unpleasant place to be. It’s an uncomfortable role to play. I certainly didn’t want it to be that way.”

He won election to Congress in 1998. But it wasn’t until the Sept. 11, 2001, attacks that Tancredo emerged as a formidable public critic of the immigration status quo.

The new platform had a price, however. At a meeting with the editorial board of The Washington Times, Tancredo remarked that if another terrorist attack was committed in the United States by foreigners and no action had been taken to clamp down on immigration by that time, “blood would be on our hands and on the hands of the president.”

When the remarks appeared in the paper the following morning, Tancredo got a call on his mobile phone from Rove. The lawmaker claimed that Rove called him a “traitor” to the president.

“I said, ‘Who do you expect people to blame — the Elk’s Club?’” Tancredo recalled saying that morning, adding, “It was a very acrimonious discussion for 35 minutes.”