In Magic there are several ways a powerful player can overcome politics, in large part because a player can choose their deck.  This makes most sense to analyze in the case of repeat play among a stable playgroup.  Here are three ways to do it:

1. **Play a deck that is opponent-count agnostic such as combo**.  You need to play combos that go "infinite" (such as [mtg: Exquisite Blood] + [mtg: Vito, Thorn of Dusk Rose]) rather than combos that get you to 20 damage very efficiently (such as [mtg: Channel] + [mtg: Fireball]).  Here, the skill is in piloting your deck, dodging two player's worth of removal, and setting off your combo before the aggro of two players can kill you.

2. **Play a defensive flavor of control**.  This involves cards that that make it obnoxious for people to attack you, like [mtg: https://scryfall.com/card/chk/10/ghostly-prison], [mtg: https://scryfall.com/card/roe/32/lightmine-field], and [mtg: https://scryfall.com/card/ddn/66/hold-the-line].  So long as you are not overtly offensively threatening, you can change the calculus for other players attacking you such that it isn't worth it.  Your goal here is likely to get the game to go to a standoff that your deck has some way to win (such as a combo or milling opponents).

3. **Play a deck that is worse**.  Reducing your threat, so long as you can publicly signal that you are doing so, will make two other rational players fight each other first.  This has solid game theory foundations.  See the [Ted Ed Wizard Standoff](https://www.youtube.com/watch?v=mmkCS5eA4f8) for a game theoretical example.