The New Yorker has a profile of Mitch McConnell that is not behind a paywall and definitely is worth a read.
Although the two men almost always support each other in public, several members of McConnell’s innermost circle told me that in private things are quite different. They say that behind Trump’s back McConnell has called the President “nuts,” and made clear that he considers himself smarter than Trump, and that he “can’t stand him.” (A spokesman for McConnell, who declined to be interviewed, denies this.) According to one such acquaintance, McConnell said that Trump resembles a politician he loathes: Roy Moore, the demagogic former chief justice of the Alabama Supreme Court, whose 2017 campaign for an open U.S. Senate seat was upended by allegations that he’d preyed on teen-age girls. (Moore denies them.) “They’re so much alike,” McConnell told the acquaintance.
Trump is a cheap, ignorant demagogue, and he soils everything and everybody he touches. McConnell is scarcely any better; he is cynical and opportunistic, but at least knows how to behave in polite company. They deserve each other.