House Democrats are making a serious mistake by rushing to a vote on impeaching President Trump rather than attempting to compel important witnesses to testify who could shed more light on what happened with Ukraine.

The public impeachment hearings have wrapped up, and Democrats are confident that they have enough to draft impeachment articles that can pass the House of Representatives. Taken together, witnesses have painted a portrait of Trump and his personal lawyer Rudy Giuliani being myopically obsessed with getting Ukraine to publicly commit to investigations related to the 2016 election and Joe and Hunter Biden. And that obsession led to an attempt to leverage U.S. foreign policy to achieve this purpose.

Witnesses provided testimony and text messages suggesting that the Trump administration dangled a White House visit in front of Ukrainian President Volodymyr Zelensky to get his commitment for the investigations. Those conducting diplomacy with Ukraine were also under the impression that Trump was delaying congressionally authorized aid to Ukraine to extract an announcement on the investigations.

But the Democrats case also has weaknesses. Though it may be Occam's Razor to assume Trump was withholding security assistance in exchange for the investigations, none of the witnesses had direct knowledge that this was the case. The closest was Gordon Sondland, the major Trump donor who was appointed to be ambassador to the European Union and had been in touch with Trump. He testified that he concluded that the security aid hold was tied to the investigations because it was the only logical explanation in the absence of any other. That is, he knew that Trump and Giuliani were obsessed with the investigations and that this was already the reason the White House visit was being withheld.

So, what else could explain the security aid hold up? That said, Sondland claims this was only his presumption, not something he heard from Trump, who at one point told him he wanted nothing from Ukraine. This is important because the best evidence that Ukraine was actually told about the link between security assistance and the investigations is that Sondland communicated this message to a Zelensky aide. When Vice President Mike Pence met with Zelensky the same day, he did not give a reason for the delay in security assistance and reassured Zelensky of strong American support, according to an account of his adviser Jennifer Williams.

Yet throughout the testimony, other names kept coming up who were closer to Trump and in a better position to know what was going on. There's Giuliani, who by all accounts (that are backed up by his the Trump-Zelensky phone call) was the point person in trying to get Ukraine to commit to the investigations. There's former national security adviser John Bolton, who, according to multiple witnesses, was disturbed by what was happening with Ukraine, describing the pressure campaign as a "drug deal" and directing those working for him to speak with the NSC lawyer. There's acting chief of staff Mick Mulvaney, who was at the center of efforts to withhold aid and at one point in a press conference said the investigations were part of the reasons for the hold. There's Secretary of State Mike Pompeo, who Sondland claims was in the loop in all dealings with Ukraine. And there's Pence. Sondland claims he expressed his concerns to the vice president that the aid pause was linked to the investigations and that Pence nodded.

The White House resisted allowing these individuals to testify, and Democrats have made the political decision that they don't want to waste months on a court battle to compel testimony. Instead, they say they will just use it to add to the articles of impeachment.

“They should be coming before us,” House Speaker Nancy Pelosi explained. “They keep taking it to court, and no, we’re not going to wait until the courts decide. That might be information that’s available to the Senate, in terms of how far we go and when we go. But we can’t wait for that because, again, it’s a technique. It’s obstruction of justice, obstruction of Congress.”

This allows Democrats to wrap up impeachment in the House by the end of the year and make sure the process doesn't drag deep into the election year, preventing them from focusing on other issues.

But this strategy is ultimately mistaken. Everybody knows that the House will impeach Trump and that there won't be anywhere near the 20 Republican votes in the Senate to remove him from office. So the impeachment process is ideally about finding out more about what happened, or from Democrats' perspective, about building as strong a case as possible to take to voters in the 2020 election.

Compelling the testimony of those within Trump's inner circle could strengthen the case against him and help those undecided weigh the very serious issue of removing a president from office. If the efforts to compel testimony fail, a long, drawn-out court process will strengthen the case that Trump is obstructing Congress and preventing the American people from finding out the full truth of what happened.

Instead, Democrats appear determined to rush a vote in the next few weeks and then kick it over to the Republican-controlled Senate, where they will relinquish control over the impeachment process. This is a mistake.