Rep. Chris Cannon of Utah is one of those caught in the cross hairs, and his case symbolizes the political perils of the immigration issue for politicians facing voters.
A dependably conservative Republican representing an overwhelmingly Republican district, his voter base includes a volatile mix of die-hard anti-illegal-immigration activists and business owners who want cheap labor.
Representatives like Cannon who support a guest-worker program are hammering home their talking points: Bring undocumented residents out of the shadows; Supply workers for the jobs Americans don't want; Remember we are a nation of immigrants.
But opponents, who want to lock the borders to unauthorized immigrants after expelling those already here illegally, are branding the Cannons of Congress with the "A" word: amnesty.
"He's misguided in his support for amnesty," GOP challenger and former Congressman Merrill Cook said about Cannon.
For politicians being sucked into this debate, there's no place to run and hide. It appears congressional leaders are set on passing some type of meaningful reform.
So while lawmakers try to walk the line, they know they're going to alienate some significant numbers of folks back home.
"You have a party base that's made up of pro-business elements and also law-and-order elements," says Kelly Patterson, director of Brigham Young University's Center for the Study of Elections and Democracy. "Now how do you satisfy both of those elements when the issue cuts right through the middle of them?"
It is, of course, a rhetorical question. The answer is: You can't.
Differing proposals: As Congress dives into the debate, there's no escaping a record on the immigration issue. Support a massive fence along the border? Allow more visas? Require employment verification?
"With his party struggling to retain control of Congress, why would [Senate Majority Leader Bill] Frist force the half-dozen or so GOP senators who are vulnerable in November's elections to cast votes on a red-hot issue - especially when the upshot may be gridlock that yet again draws attention to the Republican-led government's shortcomings?" questions Kirk Victor in the upcoming edition of National Journal.
Good question, says pollster John Zogby, president of Zogby International.
"It makes absolutely no political sense to be talking about this," he said in an interview.
Cannon - along with fellow Utah Reps. Jim Matheson, a Democrat, and Rob Bishop, a Republican - voted for a House bill last year that would heighten border security and strengthen immigration laws. The legislation would make it a felony to reside in the country illegally.
But broader proposals now being considered in the Senate push the reform in a different direction, creating a guest- worker program that would allow immigrants to remain in the country under certain conditions.
Utah Republican U.S. Sens. Bob Bennett and Orrin Hatch support comprehensive reform, though they differ in their approaches. Bennett doesn't see as "practical" any program that requires immigrants to return home before applying for guest-worker status.
Hatch, who is seeking re-election this year, supports a "properly crafted" guest-worker program but wants immigrants to return home before applying for it. Hatch missed a Judiciary Committee hearing last week over the immigration legislation, sending only one vote by proxy against a guest-worker program.
Hatch said he was speaking to a Brigham Young University law society meeting in Dallas and couldn't make the hearing.
He maintains that he wasn't trying to skip out on voting for or against any of the measures.
As for Cannon, he is running for a sixth term in a safe Republican district. But it's not the Democrats who are targeting him over immigration - it's fellow Republican conservatives, who question his stance in favor of reform that includes a guest-worker program.
It won't be the first time.
In 2004, illegal immigration was the focus of his re-election race, with anti-illegal-immigration groups angered by his 2003 AgJobs bill that would have legalized some half a million agricultural workers. They poured money into his opponent's war chest and ran advertisements.
One of those spots attempted to link Cannon's support for an agriculture guest-worker program to the terrorists behind the 1993 bombing of the World Trade Center.
Opponents also claimed that Cannon brazenly attempted to solicit donations from undocumented workers during an appearance on a Spanish-language radio station.
Cannon says he never tried to skirt campaign laws and that he made it clear only citizens could donate.
He won the race convincingly.
But this year, Cannon faces two Republican opponents: Cook, the former congressman, and businessman John Jacob. Cook specifically cites Cannon's position on immigration as a reason for running against him, and anti-illegal-immigration groups reportedly helped talk Cook into the race.
The other Republican challenger to Cannon, Jacob, lists immigration as the top issue on his campaign Web site, although the page offers no specific criticism of Cannon.
For his part, Cannon says he's doing what he believes is right.
"Utahns understand we need a solution," Cannon says. "And I am committed to finding a solution."
He says he is unconcerned about alienating single-issue voters focused on tougher immigration enforcement.
"That extreme is not my base; they never will be my base," Cannon said, insisting that he has "a perfect voting record for being hard on illegal immigration."
Critics scoff at the claim.
"Everyone I've talked to, [Republican convention] delegates, they're all totally opposed to what he's doing," says Alex Segura, head of the Utah Minuteman Project and a state House candidate.
"That is a very huge concern for people throughout his district. I know they don't like his position."
Yet President Bush's call for immigration reform that would includes a guest-worker program could provide Cannon with cover.
Polls show that a remarkably strong majority of Utahns still back Bush after giving him his largest margins of victory in the last two elections.
"I believe it is important to bring people out of the shadows of American society so they don't have to fear the life they live," Bush said Friday during a news conference in Mexico with President Vincente Fox. "I believe it's important for our nation to uphold human rights and human dignity."
Pollster Zogby says Cannon and those taking similar stands may be better off sticking with their positions, especially if they can persuade Latino voters to become politically active.
"Continue to take the moderate stance," Zogby said would be his advice. "In this way you at least cut your losses, telling voters that Congress needs calm reasoning and calm voices."