Anyone know how this would affect the Electoral College?
See, that’s the problem. The 23rd Amendment gives the “seat of the Federal government, ie. the District 3 Electoral Votes. This was passed because residents of the District had no voice in Presidential elections. Congress passing a DC statehood bill doesn’t cancel the 23rd Amendment. To give DC statehood is going to require a Constitutional amendment and that’s not likely to happen.
But if the democrats are sincere, they can easily draft such an amendment. Getting it through both House and Senate with 2/3rds majority might be tricky, even if they scream ‘racism’. Through 38 state legislatures will be even harder.