Mitch McConnell is definitely a mixed bag. Leaving the downside for some other time, the upside is that he's a great guy to have on your side when the going gets rough in the Senate.
Today he gave a speech in the Senate threatening a "scorched earth" approach if the Dems eliminate the filibuster. I had no idea that the GOP had alternatives, but it turns out that they do. Zerohedge--McConnell Flips Out Over Filibuster, Threatens 'Scorched Earth Senate' If Dems Pursue Power Grab:
If Dems 'blow up the filibuster,' McConnell says he'll require a quorum for every piece of Democrat legislation - which VP Kamala Harris couldn't become a tie-breaker for, and that previous actions would seem like "child's play."
In short, McConnell is threatening to make Congressional Democrats' lives miserable if they push for a power grab through the elimination of the filibuster, while Democrats know they'll have to negotiate in good faith if they want infrastructure - or any major legislation - to pass with the support of moderate Democrat Joe Manchin - described in January as the most powerful Senator due to this exact scenario.
That's not "flipping out." That's just splashing some cold water in your face. Looks like the GOP may have more cards in its hand than anyone thought. I sure hope so.
Zerohedge has all sorts of analysis of this, but the above looks like the bottom line.