They don't want one party rule. They want one ideology rule. Meaning they want "progressives". They need republicans because they need to have someone go along with their nonsense so that they can say it was "bipartisan" and give themselves cover. People like McConnell and McCain and Rubio and Graham and Hatch are functionally progressives. They love government and liberals love them. Because while the aforementioned Republicans will spew platitudes at election time about conservative beliefs, they never fight for anything. Oh they put up token fights here and there, but in the end, they cave and say "We will be a in a better position next time" Cruz is the worst nightmare for these bullshit republicans and liberals because he is smart and he can articulate conservatism in a way that makes them squirm AND he is willing to fight. I will be sending money to whoever primaries McConnell. Now the Joey Scarboroughs of the world will say "Oh no, we need McConnell, we want to take back the Senate", but if it is going to advance conservative principles and is only going to advance big government principles, then I am not interested.