The only rational voting strategy is voting for leftists in the Democratic primary, and then voting against the fascists in the general, even if that means voting for the neo-lib.
That strategy is only rational if you believe that voting progressive in the primary will create change faster than the status quo will kill us all. And forty years of the party continually fucking off further right at the behear of it's Wall St paymasters screams loudly that that belief is a fantasy, and your strategy is delusional.
You continue to hand power to the people making things worse and pretend you're doing harm reduction.