A president saddled with a 39 percent approval rating is not a guaranteed asset, especially in the dozens of competitive House districts where Republicans risk being drowned in a blue wave. Party strategists worry that Trump will do more harm than good, ginning up his foes more than his friends, and that his presence or endorsement may well have negligible value even in reliably red enclaves—as most recently evidenced in Ohio’s special House election and the Kansas GOP gubernatorial primary.

But Trump may not care, because, as nonpartisan political analyst Stuart Rothenberg points out, “he is simply incapable of receding into the background or allowing the midterms to be about anyone other than himself.” Indeed, Trump brings to mind a character that John Belushi played on “Saturday Night Live.” He’d show up for a party, create a mess, eat all the food in sight, overstay his welcome, and spurn every hint from his exhausted hosts that it was time for him to go. The character’s name was The Thing That Wouldn’t Leave.