Most observers expect that Trump will not announce any major policy changes on Wednesday. Instead, they think he’ll use rhetoric to try to appeal to both his base, and the new audiences he needs to bring under his tent.

A perceived shift on the issue could undercut Trump’s declaration that he’s different from typical politicians whose positions shift in the wind, and potentially disappoint his biggest fans.

“His base will not allow him to move from his previous position—his previous position was the one he staked out that distinguished himself from every Republican running,” former Ted Cruz spokesman Rick Tyler said Monday on MSNBC’s “Morning Joe.”

“What he wants to do, of course, is expand his base and get beyond his base, but his base wont let him. He’s got a low ceiling and a high floor and it’s not going to let him move much.”

Trump is giving the speech in Arizona, a reliably Republican state in presidential elections that polls suggest could be a toss-up in this year’s fight. It’s also the home to vocal Trump supporter Sheriff Joe Arpaio, an immigration hardliner.