The ones actively against. Normies ain't gonna win. Normies go with whoever wins, they're not trying to "win".

All you need (said as if that's easy) is an uncorruptable leader who listens to the lowest participants and entrants, and actively moderates away the bad actors. Keep copious backups, and tell all users to keep copious backups of their proposed changes and additions (and they're always "proposed", even when committed, it can be undone!). Weekly, the big guy comes in, looks it over, and like McCarthy, sniffs out the commies, and just IP-bans them, and reverts the code. Doesn't matter if they've contributed for a day or a decade, a stranger or a friend, too bad, you can be friends on Facebook, but not in the project, no hard feelings, ban.

Most commies are idiots and can't get around an IP ban. That clears most of them. The remainder will be bumped out and filtered around long enough that they'll either give up, seeing an environ explicitly against their hate, or you'll get a large enough "loyal" developer-base that you turn off applicants/contributors.