What do major Republican donors like Sheldon Adelson and Paul Singer have in common with Chuck Schumer and Nancy Pelosi? They are all in favor of immigration reform.

The Republican rank and file may be divided, and the prospects for the Senate’s immigration compromise in the House gloomy, but among the biggest donors to Republican causes in the 2012 cycle, there is overwhelming support for immigration reform. Many top Republican givers to the Romney campaign and to conservative super PACs are squarely behind immigration reform and only one, former Rick Santorum super PAC backer Foster Friess, is actively opposed. As former Romney campaign spokesman Ryan Williams told The Daily Beast, “a number of traditional Republican donors are speaking out in favor of immigration reform because they see this legislation as good for the party, but also good for the future of the country.” But these donors aren’t the usual RINOs and token Republicans lauded by the left. These are the guys who cut the checks to pay for tough negative ads.

Singer, a hedge fund manager and major Romney donor who has been attacked as a “vulture capitalist” by ThinkProgress, has written a six-figure check to the National Immigration Forum, a pro-immigration group. Bob Perry, who funded Swift Boat Veterans for Truth in 2004 and spent nearly $25 million in 2012, was poised to be a strong advocate for immigration reform before he passed away in April at age 80.

Even the ultimate liberal hate figure from the 2012 election, Adelson, who dumped more than $75 million into trying to defeat Barack Obama, is pro–immigration reform. In a December 2012 interview with The Wall Street Journal, the casino mogul said: “I’m pro–DREAM Act ... It would be inhumane to send those people back, to send 12 million people out of this country to disrupt a whole potpourri of family issues over what happens to the children. I mean, it’s all ridiculous. So we’ve got to find a way, find a route for those people to get legal citizenship.”

The result is a coalition of strange bedfellows, but those on the left don’t seem to mind. It’s normal for “big bills to get supported by coalitions for diverse reasons,” said Jeff Hauser, a spokesman for the AFL-CIO. It’s a natural outcome when an issue “is so important, big, and complicated,” he added.

The sheer amount of financial firepower behind the immigration-reform bill could have real consequences for those Republicans who don’t fall into line. Ali Noorani, the head of the National Immigration Forum, told The Daily Beast, “If the business community is going to put money into passing reform, they’re going to think twice about candidates that are blocking reform” in future elections. The issue is becoming so important, he said, that “organizations and individuals that spend political dollars are looking at immigration as a threshold question” in future elections.

But just because donors favor immigration reform doesn’t mean Republicans in Congress will follow. After all, Singer is strongly in favor of gay marriage, and Adelson supports “socialized medicine.” Neither of those causes are likely to gain traction among House Republicans any time soon.

However, with the August recess approaching, those donors can be leveraged to pressure members of Congress who are spending the month out of Washington. As Williams points out, business leaders in individual communities have the ear of their members of Congress. Many employ a “significant number of people in districts across the country, and members will be hearing from them.” Such a strategy is crucial to future of the bill, said Noorani. The likelihood of immigration reform passing the House “really depends what type of political space that we can create in the month of August, if conservatives weigh in at a district level for immigration reform,” he said.

After all, donors are important, but voters are even more important. Said Rick Tyler, the president of the Strategy Group for Media and a former spokesman for Newt Gingrich: “Remember, politicians don’t form parades, they jump in front of them, and there’s no big parade on immigration.”