A lot of what needs to be done is making sure that the Harris win is large enough that you can’t easily claim that a handful of ballots should be tossed and change the outcome. That means:
- Check your voter registration — part of the Republican strategy has long been invalidating registrations so people can’t vote
- Volunteer — nothing in the world quite like talking to people.
- Donate — money is used for everything from ads to voter turnout operations
- Organize; be prepared to turn out with others in your community to actively object to any effort to ignore your votes
After the fact, but it doesn’t prevent them from doing it in the first place. The federal government doesn’t care, they’re just handed the electoral votes from the states and go with it.