My money says the Leadership of BOTH Parties are up to their necks in Ukraine Foreign Aid Corruption, Bribes and Kickbacks, which is why nobody wants to play.
Trump threw a wrench into the whole cozy triad. The propaganda arm, political puppetry arm, and the money laundering pay to play arm.
That is who is desperate to impeach Trump and remove him from office. The NSA, CIA, FBI, and State Department are who is after Trump. His phones, emails, and private conversations are bugged 24/7. As are his friends, associates, relations, and counsel. There are no witnesses for impeachment. Just surveillance material they hand over to Schiff with a plausible whistle blower or 3rd party to put it to a mouth. That's why there will be no trial.