the GOP will still be there, it'll be the far right fascist Trump party. the Dems will be the party for the conservatives and moderates.
that's called shifting the overton window far right and sending the country toward fascism. the only way to prevent it was to move left in 2020.
Unfortunately I think it's fait accompli at this point.
We live in a world where a teenage girl made an impassioned plea to save hers and future generations from ecological terror citing reams of scientific data, and guys who have bumper stickers making rape jokes about her on their rolling coal trucks say, "I don't believe that." And for some reason, because those two opposing sides exist, it means the issue hasn't been decided and therefore we should not take any action.
What can you do in world like that except say, "Whoops. Somewhere along the line we fuged up. Let's let the planet try again. Maybe the cockroaches will evolve into something more rational than the apes did."