They're sheep.
Liberals only respect one thing: power.
Their power.
The liberals and the intelligentsia are the first ones to roll over when the tyrants take power. The callow and the witless that inhabit leftist territory have moved their philosophies from free elections will set you free to only our gentle guidance to the uneducated populace will set you free.
Mussolini and his platform is the precursor of modern liberalism. And we know what he did to the liberals - either suborned them or killed them. After the first few deaths, the rest hoisted their asses into the air and became the most enthusiastic supporters of the new regime.
I think that traitor is too mild a description.