I've always wondered what would happen if a President gave a TV-broadcast speech, telling people to write to their congressmen and demand a change of their policy on some issue.
Would that be illegal? Would it be speech? It's not like the President would be telling you who to vote for (though it might be different if the US had referendums, because the President would be telling you what to vote for); the President is simply attempting to sway your opinion, and then telling you to inform someone else of your (hopefully swayed) opinion.
This is exactly what I think Trump has in mind. First time congress doesn't do what he wants, he'll get on TV and list off every single congress critter that is getting in the way of Making America Great Again. They'll quickly fall in line or find themselves replaced in 2 years.
Would that be illegal? Would it be speech? It's not like the President would be telling you who to vote for (though it might be different if the US had referendums, because the President would be telling you what to vote for); the President is simply attempting to sway your opinion, and then telling you to inform someone else of your (hopefully swayed) opinion.