What happens next? I see three possibilities. One, Trump could find a new legal team. Time is absurdly short; typically, even in a routine criminal trial, the legal teams would be in endgame crunch-time mode by now — never mind for a historic impeachment proceeding. But whoever does take on this representation should understand that, if he actually raises the “stolen election” defense, he does so at his own professional and reputational risk. The “stolen election” lie fueled the Capitol insurrection on January 6 and repeating it now from the well of the Senate only threatens to provoke more unrest.
Trump also could choose to represent himself. This is extremely unlikely but legally possible. Criminal defendants can and at times do elect to represent themselves — it’s called “pro se,” in the Latin legalese — and there’s no technical reason Trump can’t do the same at impeachment. But do not count on this happening.
Or Trump could elect not to defend himself at all. There is nothing in the law that requires a person facing impeachment to have any legal representation.