McConnell is only going after Marjorie Taylor Greene as a sacrificial lamb to make the rest of the GOP look better by comparison. But the reality is she is the true face of the party McConnell leads, as evidenced by their continued support of Trump. https://www.salon.com/2021/02/03/mitch-mcconnell-isnt-fooling-anyone-marjorie-taylor-greene-is-the-true-face-of-the-modern-gop/
McConnell's swipes at Greene are about looking good to the cable news pundits while not actually doing anything to curtail the power of the Trumpist wing of the GOP, which is 90% of them and a wing McConnell belongs to, with his continued support of Trump.
McConnell can call Greene all the names he wants. But he and every other Republican who votes to acquit Trump for inciting an insurrection is just as bad as she is, and just as much in thrall the to fascistic, conspiracy theory faction that dominates the party.
That's why Republicans are so freaked out at the idea of Democrats letting victims testify about the Capitol riot. It will underscore how everyone who votes to acquit Trump is a full-blown Marjorie Taylor Greene-style monster.
As an example, Blackburn is just as unhinged a nut as Greene. She’s endorsed the lie that Planned Parenthood “sells baby parts”, a QAnon-style conspiracy theory that has led to a fatal massacre in Colorado. https://www.rawstory.com/fox-news-marsha-blackburn/