Optional
Gerrymandering, voter ID, challenging voter registrations, disenfranchising felons, opposing mail-in voting, anonymous mailers threatening to arrest voters, closing polling stations in Democratic-leaning areas, challenging voters at the polls to gridlock the polling places, making the handing out of water to people waiting to vote (in red states - where it’s hot) illegal.
All the well-known cheating tactics of republiQans. Others are less well known. That’s one of the problems.
This cannot be emphasized enough.
Even AOC was not their choice, she did it herself and beat the Dem choice.
Not the point.
She was a random no name dem at the time who knocked on doors and undercut the old fart dem incumbent for her district.
The point is that any able bodied motivated individual with the charisma who also fits the requirements for the role, say, even a bartender, can oust the old farts in office.