Grabbag: Third Party erased

Erase one of these third parties from American politics...whichever you think would have the biggest change in erasure:
Anti-Masonic
Liberty
Free Soil
Know-Knothing
Greenback
Prohibition
Populist
Socialist
Progressive
Union
Dixiecrats
Reform
No fair using Green, as that would have created President Gore.
Also "people" parties like H. Ross Perot are disqualified.

ahhhh how america would be better off without the prohibition party.