Isn't direct appointment of electors done by each state's legislature though, not the US senate? All of which are Republican controlled, though I haven't checked the actual members of each one to judge how many will cuck out (I doubt many considering how most of the GOP seems to be backing Trump now). You might be thinking of what someone else brought up, regarding the Senate:
Speaking of, can the Senate actually refuse to certify votes, or is this considered
unconstitutional? I'm not seeing anything suggesting they'd be able to do this, compared to
appointment of electors where the method of choosing electors isn't set in stone, even if traditionally it's through popular vote of the state.