Let me throw this out there. The impeachment could have been done correctly. I'm not just ripping the House Democrats without saying how they could do it right. Let's break this down.
First, they didn't want a special prosecutor and chose to investigate the matter through the House Intelligence Committee. OK, they have that right. They can do that.
Second, they chose to conduct their investigation in private and highlighted the fact that prosecutors and investigators work in private. OK, that's a plausible justification. However, they chose to selectively leak information. That isn't per se against the law, but it undermines their credibility when they claim to be serious and solemn operators.
Third, they chose to launch an impeachment inquiry from the very beginning. There isn't some big legal implication of that. However, it is a major political move. It locks them into a box. As a practical matter, once that train starts, it doesn't stop almost no matter what the evidence shows. It makes it damn near impossible for them to backpedal if things don't go exactly as they expect.
Fourth, the Intelligence Committee invited testimony from several people, but they only actually received testimony from people they knew would testify favorably. Privileges were asserted by the people who dealt directly with Trump, and the committee chose not to assert any legal remedies to compel their testimony. Well, the problem with this is that the people who testified for them knew damn near nothing relevant, because they had no dealings with Trump, and he was the guy they were trying to impeach. Sondland had some dealings, but they were extremely limited - not enough to get anything really damning if you look at the specifics. They threw a ****-fit about privileges being asserted, but that is customary. Were the assertions overbroad? Probably, but that's where the court comes it. It can sort that out, but somebody has to decide to appear in court. The House blew that off, and that was indefensible. If I operated that way, I would have been sued for legal malpractice.
So what did all that leave them? It left them with a bunch of wildly overblown rhetoric about "bribery" and "treason," but when the **** hit the fan, they couldn't come up with any statutory violations. In other words, they couldn't prove that he broke a single law. Bribery was off the table. Obstruction of justice was off the table. All they had was a catch-all "we don't like what he did" abuse of power article that isn't supported by the evidence and an "obstruction of Congress" article that is facially nonsensical.
How could they have done it differently?
1. Don't start with an impeachment inquiry. That immediately turns it into a dog and pony show. Start with routine oversight hearings. That's far less of a political **** storm, and they can still use subpoena power. Refer it to the Judiciary Committee as an impeachment matter after the evidence is found.
2. Take the process as seriously as they pretended to. Instead of calling a bunch of witnesses and having them Trump-bash and not much else, use their subpoena power to get testimony from the people who actually have knowledge of relevant facts. Yes, that takes longer, but if you actually care about what you're doing, it's the only right way to proceed. And it doesn't have to take forever. Courts can expedite matters of particular importance. They do it every frigggin' day. That's a ******** excuse.
3. Don't overstate the case, before you have the facts. Don't just start mouthing off about bribery. Have your counsel come up with questions that will elicit the testimony to prove bribery, and when you get that on the record, then you can talk about bribery.
4. Cut the ******** sanctimony. No serious person bought any of that. The matter was treated as an entirely partisan and politically-driven exercise from the beginning (which is why the investigation was so sloppy in the first place). The sanctimony only made them look like phonies.