"I think there are some Republicans that are fearful," said Ari Fleischer, the former White House press secretary who helped author the RNC report. "And they'd like to be for immigration reform, but they're worried."
These countervailing forces make for a familiar storyline, in which conservatives are pitted against party leaders—and elected Republicans stuck in between the two. How this struggle plays out could determine whether an immigration law makes its way through Congress this year.
The RNC report, which was released three months ago, was striking in its urgency—in part because as a political committee, the RNC rarely stakes out policy positions. But, as the report noted, immigration reform has become a "litmus test" among Hispanic voters, an increasingly important voting bloc that went for President Barack Obama by 44 points over Mitt Romney last fall.
But the RNC and many other instruments of Republican politics have mostly sat quietly as a bruising intraparty fight plays out on Capitol Hill.
Many other politically savvy Republicans echoed the RNC report's language on immigration when it debuted almost three months ago.
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Since then? Silence, mostly. The RNC hasn't aired any ads or posted any videos looking to give Republican lawmakers the cover they need to support the immigration reform law now before the Senate; the RNC's most noteworthy announcement involved hiring Jennifer Sevilla Korn to oversee Hispanic engagement.
"We are encouraged by the leadership from Republicans in the House and Senate working to fix our broken immigration system and will continue to work with Republican leaders to ensure the GOP message reaches the Hispanic community," said RNC Chairman Reince Priebus.
"Jennifer S. Korn will be leading this grassroots effort to engage the Hispanic community at a local level including building a long-term presence in communities across the country," he said. "As we continue to strengthen our relationship with the Hispanic community, we will address many of the issues Republicans are working on including immigration, jobs, and the economy."
Republicans are quick to note that the RNC's endorsement of immigration reform doesn't necessarily imply an endorsement of one proposal over another. And many are still optimistic about the prospects for an overhaul; House Speaker John Boehner, R-Ohio, told ABC on Tuesday that he expects a bill to pass Congress by the end of this year.
"We've come a long way in a fairly short period of time on immigration reform," said Henry Barbour, the Republican committeeman who helped author the report. "So I think we're in a good spot. I think that Republican members of the House, they'll address it fairly and fully. At the end of the day, I think we'll see legislation passed."
"In this one area, it's important to send signals and provide encouragement for people who want to be for immigration reform but are worried that it might not be popular in all corners of the Republican base," Fleischer added.
But indeed, in the talk radio and blogging communities that hold so much sway in the contemporary GOP, the immigration reform bill before Congress is mostly unpopular. Party elders' arguments in favor of immigration reform have done little to silence conservative critics of immigration reform.
Similar uproar from conservatives was a primary factor in President George W. Bush's failed immigration overhaul last decade. The question is whether the conservative grassroots can again prevail over immigration reform proponents among the party establishment.
The Senate voted 82-15, with the support of 27 Republicans, to begin debating the bipartisan "Gang of Eight" proposal on Tuesday. It's a very open question as to how many of those Republicans will still stand behind the legislation come July 4, when the debate is slated to wrap. The number of Senate Republicans who support the final product could sway colleagues in the GOP-controlled House. A small tally of GOP-ers could worry House conservatives, while a higher number would provide House Republicans with more political cover.
Conservatives have been organized from the outset against the proposal. Heritage Action, the political group associated with the Heritage Foundation, which is now headed by conservative stalwart and former Sen. Jim DeMint, is vehemently opposed to the legislation, and a small coterie of Senate conservatives has loudly denounced the plan in floor speeches and media appearances.
There are efforts underway, though, to help give Republicans some cover.
Florida Sen. Marco Rubio, a member of the Gang of Eight, has been a leading advocate of comprehensive immigration reform to conservatives. Sen. John McCain, R-Ariz., another longtime advocate of immigration reform, has also been outspoken about how essential reform legislation is to the GOP's long-term health.
And conservative groups like the Chamber of Commerce and Americans for Tax Reform have taken a more prominent role in pushing immigration reform right now. The Karl Rove-linked super PAC American Crossroads even spent $100,000 on ads in favor of immigration reform this week, the first time the group has found itself endorsing a part of Obama's policy agenda.
And Republicans for Immigration Reform, a super PAC founded by former Bush administration Commerce Secretary Carlos Gutierrez and former Romney super PAC leader Charlie Spies, will emerge from its dormancy for much of this year to help lay the groundwork for reform.
Republicans for Immigration Reform (R4IR), Spies said, would debut new polling on Thursday demonstrating support among conservatives and Republicans for immigration reform. The group has run some advertisements in South Carolina, the home state of GOP Gang of Eight member Lindsey Graham. Spies said R4IR would likely air even more advertisements targeted toward specific House districts once the Gang of Eight bill reaches the lower chamber, where conservatives are less beholden to leadership and more closely hew to the GOP's grassroots community.
"Conservatives increasingly understand that we have a de-facto amnesty system in America. And it is going to have to be reformed," Spies said. "Republicans can be a part of those improvements to the existing system and take credit for improving the immigration system, or they can be painted by Nancy Pelosi and other partisan Democrats as obstructionists, which is a losing proposition as we look to grow our party."
—By Michael O'Brien, NBC News