The assumption behind the Trump-might-drop-out chatter is that the president would want to avoid the psychological sting of a loss, but he’s already signaled how he’ll handle a defeat—by saying he was robbed.
With this rationalization in his back pocket, there’s no reason for Trump to forgo any chance whatever of remaining the most talked-about man on the planet for the next four years by dropping out based on early summer polling.
The anonymous Republicans chattering about this scenario surely are wish-casting and assume some other—any other—GOP presidential candidate would be better for the party’s chances. This, too, is doubtful.
How would the great drop-and-switch even work? The party would be implicitly conceding that the incumbent Republican president was such a disaster that he couldn’t even run for a second term—and then turn around and ask voters for four more years of yet another Republican president.