Why aren't the Democrats in the House calling the witnesses Schumer wants called?

Democrat Chuck Schumer is saying that unless the Democrats get a do over in the Senate and can call new witnesses the process is unfair.

But if Schumer knows of witnesses that would actually make a case that Trump did something criminal why hasn't he told Jerry Nadler about them? Why haven't the Democrats paused their impeachment train wreck to call those witnesses?

The answer is that the entire impeachment process is nothing more than a political ploy to try and smear Trump before the 2020 election and the longer the Democrats dwell on it the worse the opinion  of we the people about the process is.

Effectively Schiff's impeachment hoax was deep sixed when Trump released the transcript of the phone call and the Democrats have been improvising since.

Since we the people aren't stupid the longer the House Democrats are on stage denying the President his Constitutional rights, saying the Supreme Court doesn't understand the law, and denying Republicans the right to call witnesses, all while saying that Joe Biden's actions in the Ukraine aren't worth looking at the more we realize that the Democrats are attempting to overturn the 2016 election.