They don’t need evidence. They need a simple majority by the cabinet and 2/3 majority by congress. It’s a political process. If a majority of the cabinet agrees, they transmit that to congress. Congress votes. A 2/3 majority confirms the decision.
There’s no fundamental difference between the process for the 25th and impeachment + senate conviction.
Not until you find a prosecutor who is incapable of embarrassment at pursuing such a stupid case and has no shame participating in political prosecutions.
And who determines that? A majority of the cabinet and a 2/3 majority of congress. It can be because they think his tweeting results in him being unable to fulfill his duties.
A discussion on whether the President is compromised by a hostile foreign government, and the potential need to remove him through a Constitutional i.e. COMPLETELY LEGAL process, is NOT sedition. Get that through your skull.