Republicans are so far treating him with the deference they displayed while he was in the White House as they wait to see if he makes his move.

On Saturday afternoon, Mr. Trump heads to Iowa for a rally at the state fairgrounds, a perennial stop on the presidential campaign circuit. Joining him will be several of the state’s top Republicans, including Gov. Kim Reynolds, Senator Charles E. Grassley and the chairman of the Iowa Republican Party, Jeff Kaufmann — a testament to the former president’s enduring dominance.

Mr. Trump’s unwillingness to cede the spotlight has cast doubt on the political futures of an entire group of Republican politicians who have suggested that they might someday want to run for president. And while they — like the rest of the country — can’t be sure what the notoriously fickle former president might do, some of them are trying to stake their claims as leaders in the party.

That requires a good deal of delicacy on their part. And it got a little awkward this week for two of them.