If there’s a question about Republicans being able to win national elections it’s not because of electability. It’s because the game is now permanently rigged against them.
From 2020 forward, the only Republicans who win elections will be those the Democrats allow to win. The Democrats will need token opposition. From time to time it may appear that the Republicans have the upper hand, but the Democrats will always be in control.
I think it is once the Dems take over the political system of a state (Like my State of Washington) they will take over the election system so it only takes a huge margin for the GOP to win an election. Our last Secretary of State, Republican, Kim Wyman, resigned to work on election security at the Cybersecurity and Infrastructure Security Agency in the Biden administration. As a Republican, we think Wyman was a mole for the Democrats.