The idea of a Labor vs. Conservative configuration could be viable, if the political focus shifts left. The Labor Party you describe would pull the focus that way. Considering that the US has always been on the conservative end of radical, historically (democracy=radical on the larger stage of history), I'm not sure the move left would be all that severe.

I can't see old-school liberals in a Conservative-style Democratic-Republican Party with the hard right wing. They'll all break out in hives.

Do you believe that the far right will be absorbed into smaller parties like the Constitution Party? I don't believe they'll shut up and go away. Nor -- and it pains me to say that -- should they. It's a free country.

We've weathered Mexican political upheavals before.