Twitter frequently selectively enforces its own terms of service. They punish some users and then intentionally let other users get away with atrocious behavior with no consequences. I've witnessed this across hundreds of various Twitter accounts over the last several years, so the number of times this happens must be rather epic. Numerous agencies of the US Government can choose to pursue Twitter for that. Twitter will find it impossible to correct their chaotic, selective, biased approach to how they treat their users so very differently. Angency N from the government slaps Twitter with an increasing fine each time they fail to properly, equitably enforce their terms of service. Start at $100 million and double it with every violation. Twitter will be bankrupt before a month is out.
Twitter would get on their knees and beg for mercy almost instantly. The US Government can break any corporation it wants to, anytime it wants to.
If the Trump Admin wants to be really devious, Nixonian, they'll target the executives operating the companies. Sending the IRS & Co. to make their lives a living hell. These companies will capitulate instantly.
Just ask the PRISM companies how this works in reality: you have no choice but to bow. It all depends on how nasty the Feds are prepared to get.