Just how badly has the Evil Party screwed up the impeachment?

This badly.
The witness was Charles Kupperman, a deputy to former national security adviser John Bolton. Other than Bolton himself, Kupperman is one of the officials most likely to have direct knowledge of an alleged quid pro quo on aid to Ukraine. After subpoenaing him last fall, the House withdrew its request before the court could rule on compelling his testimony for the record. The House also decided not to subpoena Bolton or any other key witnesses in the administration. Judge Richard Leon dismissed the case before New Years Eve with a hint of frustration, if not bewilderment, that the House did not seem interested in hearing from a possible eyewitness. Historically, that lack of attention in not only witnesses but also a triable case will remain one of the most baffling blunders of this impeachment. 
... 
Schiff is not the only Democrat undermining the case for the obstruction article. Representative Eric Swalwell, who seeks to be a House manager at the Senate trial, recently declared that not only should a sitting president be impeached if he goes to the courts rather than submit to Congress, but that contesting demands for evidence is actually evidence of guilt on all of the charged offenses. In a complete denial of the critical concepts of the rule of law and due process, Swalwell claimed “we can only conclude that you are guilty” if someone refuses to give testimony or documents. It is unclear if his concept of due process would be extended to President Obama, who refused both critical witnesses and documents to Congress on the basis of claims that were eventually dismissed by federal courts as untenable. Likewise, former Vice President Joe Biden has made headlines by declaring that, if subpoenaed, he would defy the Senate. But someone must have explained to Biden that the man he seeks to replace was just impeached for defying the House, even without a subpoena, because he clarified his earlier remarks by stating the opposite in a later interview.

Why, you'd think this was being done by a bunch of incompetent partisan hacks or something...