The signal that McConnell and the Republican Establishment sent, is that if the plebes do not vote for their selected choice to fill a seat, and choose instead, someone they cannot count on for Establishment loyalty - they will make sure the Democrat wins.
And the easiest and least inexpensive way to castrate Conservatives is via unprovable Bimbo allegations, preferably many decades in the past.
Because better for the oligarchy if Democrats hold the seats than for a potential Conservative and non-establishment player becoming a cog in the greased wheels of Corruption that run the Fleecing Operations of the country.