Thanks to two weeks of public hearings in the House impeachment inquiry, we know a lot more about the Trump administration’s campaign to pressure the government of Ukraine.

But we still don’t know is whether any Republican lawmaker is interested in a good-faith search for the truth.

Under oath, witnesses publicly confirmed that there had been an irregular diplomatic channel with the struggling democracy that solicited Ukrainian interference in the 2020 election. They reported that authorization for this effort came from the president himself, sometimes from his own mouth, other times conveyed through his personal attorney, former New York Mayor Rudy Giuliani.

According to the witnesses, a White House meeting between the president and his Ukrainian counterpart had been withheld for leverage, and so was $400 million in military aid to the country engaged in a shooting war with Russian-backed separatists. The demand was that Ukrainian President Volodymyr Zelensky personally announce a criminal investigation into a Ukrainian gas company and its one-time board member Hunter Biden, son of former Vice President Joe Biden, the front-runner in the Democratic presidential primary.

Instead of trying to figure out what happened, Republicans on the House Intelligence Committee acted like the president’s defense lawyers, looking for any opportunity to sow doubt in the process, ignoring the evidence. On the Senate side, almost all the Republicans signed a letter calling the impeachment inquiry “unprecedented and un-American” before a single witness had been sworn in. Senate Judiciary Committee Chairman Lindsey Graham tweeted Thursday that he is conducting his own investigation into Hunter Biden, giving the Trump re-election campaign the kind of political ammunition they were trying to get from Ukraine.

Maine Sen. Susan Collins did not sign that letter, and she has announced that she will stay silent on impeachment, anticipating a trial in the Senate in which she would be serving as a juror. But she doesn’t have to express an opinion on whether Trump should be removed from office to acknowledge that the inquiry into his actions has been justified by the facts. And there is nothing stopping her from defending Congress’ oversight role by demanding that the executive branch honor subpoenas and release documents and witnesses relevant to the investigation.

Based on the evidence already brought to light, House Speaker Nancy Pelosi did the right thing by opening an impeachment inquiry. The testimony of 11 witnesses, including a number of high-ranking, nonpartisan career public servants, provided key pieces of the puzzle. The reconstructed transcript of a phone call between Trump and Zelensky, in which Trump says “do me a favor, though” and investigate the Bidens, has been put into context. And the administration’s refusal to cooperate with investigators clarifies the picture.

Republicans should stop debating the process and examine the evidence. The only debate that matters now is whether president’s conduct meets the constitutional definition of “high crimes and misdemeanors” and warrants his removal from office.