Arguably no issue has done more to undermine Rick Perry’s presidential campaign than a Texas policy that offers in-state tuition to the children of undocumented immigrants. And no candidate has done more to exploit this revelation that the Republican frontrunner, Mitt Romney, who’s relentlessly attacked the very idea of public aid to those he derisively labels “illegals.”

What goes around comes around, Mitt.

The Massachusetts healthcare law that then-Gov. Mitt Romney signed in 2006 includes a program known as the Health Safety Net, which allows undocumented immigrants to get needed medical care along with others who lack insurance. Uninsured, poor immigrants can walk into a health clinic or hospital in the state and get publicly subsidized care at virtually no cost to them, regardless of their immigration status. The program, widely supported in Massachusetts, drew little attention when Romney signed the trailblazing healthcare law. But now it could prove problematic for the Republican presidential hopeful, who has been attacking Texas Gov. Rick Perry for supporting educational aid for children of undocumented immigrants in Texas. “We have to turn off the magnet of extraordinary government benefits,” Romney said at the recent Fox News-Google debate in Florida.

Oops.

Now, just to be clear about this, I happen to agree with Romney — at the least the 2006 version of him — about this, and I support the Massachusetts policy.

But in a political context, it would appear the former governor has a problem. After a month of condemning programs that provide state aid to undocumented immigrants, even blaming the aid for increasing illegal immigration, this new report shows that Romney’s health-care reform law — his only meaningful accomplishment in public office — provides at least some limited, taxpayer-subsidized health care assistance to these same undocumented workers.

The same state health care program covers abortion services, and served as the blueprint for President Obama’s Affordable Care Act.

Romney’s willingness to hire undocumented workers to tend to his lawn has caused him some headaches. These new revelations appear to be much worse.