This isn't true. Both the Republicans and Democrats have had phases where they opposed the right wing. Lincoln was friends with Marx and FDR fought the Nazis. Also, it's extremely damaging to draw equivalence between a flawed ally and an enemy you share no common ground with.
REALLY? Is that how you would describe the fascist apartheid regime currently engaging in genocide and myriad other crimes against humanity on a daily basis? A flawed fucking ally?
You genocide-denying apologists are fucking wild! 🤦🤬
Two neoliberal parties, each allowed to accept massive donations from lobby groups, without ranked choice voting to punish them. While they've built managed democracies the world over, nowhere gives them wet dreams like America.