https://www.siliconvalley.com/2019/11/03/magid-why-it-makes-sense-that-twitter-is-banning-political-advertising/

In a series of Tweets (because 240 characters isn’t enough for him), Twitter CEO Jack Dorsey announced that Twitter will no longer accept political ads, as of November 22. That includes ads from candidates and issue ads. Twitter will continue to accept ads that encourage voter registration.

Dorsey said that “political message reach should be earned, not bought” adding “some might argue our actions today could favor incumbents, but we have witnessed many social movements reach massive scale without any political advertising.