I mean even if there was a succdem labor party it couldn't get enough traction geographically to meaningfully challenge the Democrats, which it would have to because of the Senate and the electoral college, because too many people in the burbs and in the sticks are brainwormed into culture war bullshit. If the Republican party failed today its factions would just end up reconstituting themselves in a different arrangement because of it, like, say, with the concerns of the libertarian right placed above the evangelical right.