What do you want to have replace it?
Ideally the interventionist neoliberals who dominate the GOP would join their compatriots in the Democratic Party and the left would break from the Democrats to form a real Labor Party.
What do you think would replace it?
I don't think the Republican party is going away any time soon. The last time the US lost a major party was during the Civil War; I think it would take a similar calamity to destroy either of the established parties. Perhaps this bizarre election season presages greater political upheaval. It's not impossible to imagine some kind of "American Revolution" or "American Civil War" breaking out in the near future if current trends continue. That kind of break with the present would certainly dislocate the current parties, but would so monumental that it's impossible to predict the character of what replaces them without indulging in speculating particular scenarios.
