As for Walker? Trump has him shook. On birthright citizenship, the Wisconsin governor has had three different answers. At the Iowa State Fair, he told MSNBC’s Kasie Hunt that he wanted to curb the practice. “To me it’s about enforcing the laws in this country. And I’ve been very clear, I think you enforce the laws, and I think it’s important to send a message that we’re going to enforce the laws, no matter how people come here we’re going to enforce the laws in this country,” he said. The following Friday he told CNBC that he wouldn’t take a stance on the issue. And this past Sunday, he told ABC’s George Stephanopoulos that he doesn’t want to repeal or alter the provision at all. It’s clear, at this point, that he just doesn’t know what to say.

In fairness to Walker, Trump overlaps with his base—working-class and downscale whites. To a large degree, Walker has been shut out by Trump’s rise; with Trump in the race, it’s hard to get a hold with these voters, who prefer the flamboyant reality television star to the staid Midwestern politician.

But even without Trump, it’s not clear that Walker could sail the rocky waters of a presidential campaign. At the GOP debate, for instance, he gave an answer on abortion that—if he’s the nominee—could come back to haunt him. After moderator Megyn Kelly asked if he would “really let a mother die rather than have an abortion,” Walker dodged the question entirely. “I’ve got a position that’s consistent with many Americans out there in that I believe that that is an unborn child that’s in need of protection out there,” he said. “And I’ve said many times that that unborn child can be protected and there are many alternatives that would protect the life of the mother.” That dodge—and the implication, to some ears, that he would let the mother die—is fertile ground for any Democrat who wants to use it.