No matter how many people try to tell them they have been played for fools, much to their annoyance, that is not a conclusion they seem likely to reach before Mr. Trump even marks his 100th day in office.

They knew all along that they were not voting for a man with concrete convictions. And they continue to see that lack of rigidity — his preference for the transactional over the dogmatic — as a quality they want in a chief executive.

So while much of the country sees the swerving on policy as another sign of White House dysfunction, many conservatives shrug it off as esoteric jockeying over foreign alliances, currency manipulation and economic policy. They are focused more, they say, on what they see as a litany of recent victories…

“That does tend to bond them to him — every day they see him attacked,” said Tim Phillips, president of Americans for Prosperity, which is backed by the billionaire Koch brothers. The group has been canvassing voters recently in the suburban Atlanta district that will hold a special congressional election next week that many see as a bellwether for Mr. Trump’s popularity.