It is only about flexing political muscle. However that's done, that's what needs to be done. Phone calls, videos, the big guy making calls, appearances, rallies, whatever it takes.
But don't rely on the lawyers.
Fuck the lawyers.
United States Constitution, Article I, section 3, clause 7: “judgment in cases of impeachment shall not extend further than to removal from office, and disqualification to hold and enjoy any office of honor, trust or profit under the United States.”
It's right there in the freakin' Constitution, people. It applies to federal offices, not state or local. Federal. Like the presidency.
Can they do it once he's out of office? These people can do anything, they've already showed us that. You think the Supremes will stop them? They're more likely to sing a pretty song than do that. And who else is going to stop it? No one.
We shouldn't think there's something in the system that will stop this. It's political, not legal.
It's this guy: https://www.dhs.gov/exceptional-service-2019 (middle guy in second picture).