Of course, comprehensive immigration reform involves much more than H-1B visas. But the tech giants supported comprehensive reform, with its increases in unskilled immigration, its legalization of currently illegal immigrants, its path to citizenship, its byzantine agricultural provisions and much, much more because they wanted the H-1B boost.

For a long time, opponents of comprehensive immigration reform have thought: Why shouldn’t the Republican-controlled House pass an H-1B expansion as a stand-alone bill? If the tech people got what they wanted, would they — and their millions of dollars — really stick around to fight hard for the rest of comprehensive reform? Passing an H-1B bill would be an excellent way to split the fragile pro-reform coalition.

Now, it looks as if that could be happening. On March 19, the executive director of Compete America, Scott Corley, published an op-ed urging lawmakers to pass the SKILLS Act, which is a measure to increase H-1B visas. “There is widespread agreement among both parties and in both chambers of Congress that high-skilled immigration is good for the economy,” Corley wrote. “Congress needs to act now.”

The move set off alarm bells among Democrats. If the tech people were to pull out, and take their money with them, or even if they just lost their passion for the fight — where would that leave the tenuous reform coalition? In a much weaker position.