The House of Representatives is expected to vote Wednesday to impeach President Donald Trump, which would make him only the third president in U.S. history to be impeached. WGBH Morning Edition Host Joe Mathieu spoke with Congresswoman Katherine Clark ahead of the House's historic vote. The transcript below has been edited for clarity.

Joe Mathieu: Do you already know what you plan to say today on the House floor?

Rep. Katherine Clark: I do. I have given it great thought. And it will really be about where we are and what this vote means. And I'm going to talk about that this is a vote borne out of great fear for our democracy and our future. But it's also one borne out of optimism — that if we stand today for the rule of law, if we stand to make sure that we are always a government for and by the people, then we are going to continue to be a country that will strive towards our ideals of equality, justice and opportunity for all.

Mathieu: How do you rationalize the fact, Congresswoman, that not a single Republican member plans to vote in favor, as far as we know today?

Clark: I really can't. I think it is one of the most disappointing and dangerous parts of this impeachment inquiry to see Republicans who certainly, I hope, have read our Constitution [and] have listened to this president be willing to be complicit in his using of foreign aid for his own political gain. The very tenets of our government and what we share as Americans — those values of democracy and what that means — are at risk by this president. And I hoped that as the facts came out and they were uncontested that Republicans would put aside partisanship and vote for the Constitution and a belief in the United States of America.

Mathieu: Congresswoman, President Trump sent a letter to Speaker Pelosi yesterday. I'm guessing you've had a chance to read it. It's pretty long. And he claimed that more due process was afforded to those accused in the Salem Witch Trials. Now, I read "The Crucible," Congresswoman, what do you think he meant by that?

Clark: I have to confess that I couldn't understand most of what the president wrote in that letter. It is difficult to follow. But I think that the president has not been able to contest the facts of what we have before us: that he betrayed his oath of office, he threatened the integrity of the 2020 elections, and he used military aid to try and extort an investigation from Ukraine for his own political gain. The president keeps telling us who he is and we have to believe him. He told us in June that he would take foreign political dirt again and that he would not report it to the FBI. We all know about this call in July saying, "do us a favor, though." And then he stood on the South Lawn and said that not only should Ukraine investigate political rivals, China should, too. His [acting] chief of staff, Mick Mulvaney, said they did this and we should all get over it. We're not going to get over it, because that would be a surrender of our democracy.

Mathieu: Congresswoman, as part of the Democratic leadership in the House, can you give us a sense of [the] timeline today? Do you expect a vote will happen before the end of the day?

Clark: I think it may go into the night today. We are scheduled to have six hours of debate before we take up the votes. If all of that goes as planned, we should be voting around 6 p.m., but 70 Republicans have signed a letter promising that they will use all sorts of procedural delays on the vote today. So we'll see what they do. I hope that we can proceed in a way and a manner that is respectful and that reflects the somber vote that we're taking today. That will be up to the Republicans.