Traditional pillars of the Republican base, such as police groups, evangelical pastors and the U.S. Chamber of Commerce, have begun to push skeptical GOP lawmakers to change federal immigration laws to allow most of the nation's 11 million illegal immigrants to apply for legal status.
The issue has long been fought mostly between Republicans and Democrats. But the fate of a potential immigration overhaul may be determined by battles erupting inside the GOP.
"Now it's conservatives versus conservatives over how much immigration reform should happen," said Alex Nowrasteh, an immigration expert at the Cato Institute, a libertarian think tank in Washington that has advanced a free-market argument for opening up the immigration system.
President Obama has vowed to revise immigration laws early in his second term, but Republican support would be necessary to pass any significant legislation in the GOP-held House.
Some national Christian organizations, law enforcement officials and business leaders have begun coordinating a national campaign to convince voters that immigration reform can be consistent with conservative values. Gathering in Washington last week, leaders of several groups said the goal is to help Republicans in Congress who fear being voted out of office if they support legal status for illegal immigrants.
Called the "'I Was a Stranger' Challenge," the campaign is supported by several major Christian groups, including Sojourners, the National Assn. of Evangelicals and the Southern Baptist Convention. Many oppose abortion and gay marriage.