Congress could repeal section 230, bring back the republication doctrine, and hold online platforms civilly liable when the underlying content it itself civilly actionable.

But even as far as civil law goes, the posters themselves probably don't have any obvious liability, and under criminal law it's hard to see how they'd fall under either of the relevant extremely narrow exceptions to the First Amendment (incitement or true threat).

Unless the (former) politicians saying these things can plausibly garner the support of 2/3rds of both houses of congress and 3/4 of the states I don't see why we should pay much attention to their "demands".