Moving an immigration overhaul through the House will be difficult enough for the Republicans without opposition from Washington’s most influential conservative advocacy groups, so it might be welcome news to GOP leaders that that’s one hurdle they might not have to contend with.

On contentious fiscal matters that have come before the House since the Republicans assumed the majority in 2011, the Club for Growth, FreedomWorks and Heritage Action for America have been successful in shaping the opinion of House conservatives and in some instances, blocking undesirable legislation over the objection of GOP leaders. But two of these groups have signaled to CQ Roll Call that they intend to sit out the immigration fight.

Philosophically, it’s not surprising that libertarian, free-market oriented organizations such as the Club for Growth and FreedomWorks confirmed to me late Monday that they have no position on the immigration policies currently being debated in the House and Senate, nor do they intend to be active either supporting or opposing the legislation that is expected to emerge. But given how much influence these groups have had over congressional Republicans in recent months, their inaction could prove significant.

Three prominent tea-party-aligned Republicans at the center of bipartisan efforts to produce an immigration rewrite — Sen. Marco Rubio of Florida and Reps. Trey Gowdy of South Carolina and Raúl R. Labrador of Idaho — are typically in harmony with the key-vote alerts regularly blasted out by the Club for Growth and FreedomWorks. The club in particular has threatened to recruit and fund GOP primary opposition to congressional Republicans who slip too low on the group’s legislative scorecard.

However, that still leaves Heritage Action, which is on record as opposing both a “comprehensive” approach to overhauling the nation’s immigration system and anything that can be interpreted as providing “amnesty” to the millions of undocumented immigrants who currently reside in the United States. It’s unclear how Heritage Action might express its opposition, but the group in the past has sought to make its case on the air and through local media outlets.

“Heritage Action is opposed to a comprehensive approach; instead, we believe Congress should pursue a step-by-step process. Any legislation should welcome lawful immigrants and encourage their full participation in American life. Amnesty, in whatever form it takes, is a non-starter. Amnesty not only discourages respect for the rule of law, but it encourages future unlawful immigration and treats law-breaking immigrants better than law-abiding immigrants,” Heritage Action spokesman Dan Holler said. “Congress needs to demonstrate it can grapple successfully with things like border security and lawful immigration reform.”

Additionally, there are several other anti-immigration overhaul groups that will likely seek to pressure Republicans into opposing any immigration overhaul that offers legal status to illegal immigrants currently living in the U.S., which any bill is almost sure to do. In fact, finding a way to address the millions of undocumented immigrants living in the country is among the primary motivators for rewriting the nation’s immigration laws.

Still, attempting to do so absent opposition from among the most powerful conservative advocacy groups could make it that much easier, especially given the politically sensitive and complicated nature of immigration legislation.