So Mitt Romney was overheard the other day saying it might be a good idea to come up with a “Republican DREAM Act,” such as the one being worked on by Marco Rubio, in order to make inroads with Latinos in the general election.

But Kansas secretary of state and Romney immigration adviser Kris Kobach — who is widely respected on the right as a spokesman on the issue — told me yesterday that any such proposal is “unacceptable” if it confers any legal status on illegal immigrants en masse. This is a big deal, because if Romney sticks to Kobach’s standard, he may have little room to pivot on the issue.

Today, Rubio was asked at a forum if his proposal passes Kobach’s test. As Evan McMorris Santoro reports, Rubio said it does:

All it does, it takes something that already exists, which is it takes non-immigrant visas and applies it to children who have grown up in this country, who we spent thousands of dollars educating … [and] allows them to continue to contribute to this country and if they eventually decide they would like to become residents and then thereafter citizens, allow that to do that the same way that anybody else in the world would be able to do it, and that is by accessing the existing route that is now in place.

But does this pass Kobach’s test? Crytsal Williams, the executive director of the American Immigration Lawyers Association, tells me it doesn’t.

We have not seen the Rubio proposal yet. But his plan, as he describes it, does appear to confer legal status on illegal immigrants.

Rubio said today that his plan gives non-immigrant visas to children who have grown up with illegal status in the United States. There are various forms of non-immigrant visas; some are for workers; others for students; still others for tourists. They all confer temporary legal status provided the recipient follows certain guidelines.

By all indications, Williams tells me, Rubio’s plan would confer indefinite legal status on formerly illegal immigrants. A non-immigrant visa confers legal status, and Rubio is suggesting their new status would be open-ended.

“I don’t see how Mr. Rubio’s proposal can possibly pass the Kobach test," Williams says. “His proposal allows the DREAMers to remain in the U.S. legally.” The DREAMERS are the one million to two million people who were “brought here by their parents and have the ability to contribute to the country and are out of status right now.”

“Rubio’s proposal would give them status,” Williams says.

Of course, it’s always possible that Kobach will relax his standard. But if he doesn’t, there’s a dilemma here for Romney. If he sticks with Kobach’s rule, and doesn't embrace Rubio’s proposal, then he can’t really moderate on the issue in any meaningful sense. “Kobach leaves no room for him to pivot,” Williams says.

If Romney embraces Rubio’s proposal, then he’s stiff-arming his own immigration adviser and could anger conservatives who don’t want him to pivot on the core issue of legal status; Romney may get pilloried for breaking his promise to oppose “amnesty” at all costs.

The third possibility is that Rubio’s proposal could somehow avoid confering legal status. But then it would be largely meaningless to Latinos. “If it doesn’t confer legal status, then it’s not a proposal,” Williams says.

Romney may very well dump Kobach and/or his standard. But for now, Romney’s decision to embrace Kobach and his ideas to get through the primary appears to have left him stuck with the hard-liner, with no clear way of disentangling himself.