No evidence to support this, that's why it's both sides, false equivalence, bullshit...son.
If it were Schumer and Hillary (or Biden, your choice), we would be hearing the same things from their mouths as that of Republicans, right now.
Republicans are on the record from Feb of '16 on their 'principle'. Let's hear their explanations as to why it doesn't apply now.
This is too easy. The GOP will come out looking like even more unprincipled, double talking, assholes than they've already revealed themselves to be.