Move some of your stake off chain to anonymous voting accounts that cannot be traced back to you. If you use your upvoting power to curate you can earn rewards that cannot be touched even by a whale. Then you can use your downvoting power without any fear of retaliation.
If everyone did that, there would be no one to retaliate against. 1000 Dolphins equals 5 million SP. That's enough to nuke almost any whale account.