Former Massachusetts Governor Bill Weld has officially announced that he is running for President in the 2020 Election. Weld plans to run as a Republican, making him the only official Republican candidate running against President Donald Trump. Morning Edition host Joe Mathieu spoke with Governor Weld about his presidential campaign. The transcript below has been edited for clarity.

Joe Mathieu: So how do you run against a president with, as we keep hearing, a near 90 percent approval rating among Republicans?

Governor Bill Weld: Well, he's got very good approval ratings with the Republican state party leadership in the various states because they're taking dictation from Washington. Those are not the people, in my view at least, who are going to be deciding the election. There's all kinds of people who have nothing to do with the official apparatus of the Republican state parties who are going to be voting in the Republican primary, because let's face it the president's somewhat controversial. And there [are] a lot of people who have not been heard from, in my view. The Millennials and the Gen X-ers have not really been heard from. I think 49 percent of Millennials voted in 2016. That number should be 75 or 80 percent, and you'd get quite a different result if you polled the Republican primary with those voters being in it. So, the shape and size of the electorate that's going to be voting in 2020 is absolutely critical, and that's something that I aim to influence.

Mathieu: That would also require you to change the voting demographics of the Republican Party, no?

Weld: Well, not so much in places like New Hampshire where they permit crossover voting. That's what happened when I ran in Massachusetts. Independents came in in great numbers to the Republican primary and voted for me by margins of 6 to 1. Now if something like that happens, you're going to have quite a different poll result.

Mathieu: We remember you here in Massachusetts as a Republican, but of course you ran as a libertarian last time around. You had a lot to say about the status of the Republican Party. You're obviously not a Trump fan, but you're coming back to the GOP?

Weld: Well, that's right. My politics haven't changed, my beliefs haven't changed at all, and I want the Republican Party to be the party of Abraham Lincoln, not the know-nothing party that says climate change is a hoax and we're not going to worry about this and all we're going to do is be very angry all the time. I think that's the wrong way for the inhabitant of 1600 Pennsylvania to act. He does seem to have all of official Washington terrified of him. But is that really the purpose of a president? Maybe it's the purpose of a dictator, but it's not the purpose of a president of the United States. And beyond a certain point that's no longer style. That's substance. So I think, frankly, it's going to be good for the country to have somebody go right at the president and cross-examine him on why he's doing this and why he's not doing that. It's almost like “The Emperor's New Clothes.” And I'm very happy to play that role. This feels right to me.

Mathieu: That would be quite a show, Governor, to go head to head with a man who does not follow the normal rules of politics, never mind normal interpersonal communication. Have you figured out what nickname he'd give you yet?

Weld: Yeah, it would be very interesting. It would be two large, orange men going at each other who have absolutely nothing in common. It would be theater. No, I don't know what nickname is going to come my way, but we're preparing a list on the other side. All consistent, of course, with the dignity of the office that the president holds.

Mathieu: The point is it's a street fight with Donald Trump, isn't it?

Weld: Well, yeah. But I was a federal prosecutor for seven years, and didn't really take a lot of prisoners myself. We had different agendas. My agenda was to keep the politics out of law enforcement, and his agenda is to have law enforcement politicized so that Jim Comey has to be personally loyal [to him]. He wanted Jeff Sessions to watch his political skirts. That's not the job of the attorney general of the United States. The job of the attorney general of the United States is to do justice without fear or favor. That's the motto of the Justice Department. And I think one of the most troubling things about the president's performance in office is his mockery of the idea of the rule of law. The rule of law really undergirds not only our democratic institutions, but also our economic situation. The reason everybody wants to do business with America all over the world — and they do — is because they know that their property interests are protected by the rule of law. So once you turn your back on the rule of law, it's a slippery slope.

Mathieu: Bill Weld, you're in a club of one right now. Do you want it to stay this way, or do you suspect you'll inspire other Republicans to primary Donald Trump?

Weld: Well, I don't know. I had very nice talks with both Gov. Kasich and Gov. Hogan recently, and those are two excellent people with a lot of executive experience. I would welcome them to get in as well. Obviously, that would be a very respectful discussion. And maybe if somebody emerged stronger than the others, maybe that would influence the shape of the final against Mr. Trump. But that's all guesswork. People sometimes ask me [if I'm] surprised no one else has raised their hand. For the longest time I was nonplussed by that question. But I finally decided, yeah, I am surprised. It's pretty obvious that a lot of things need doing in Washington that are not being done. So I'm looking forward to the campaign. I am happy.

Mathieu: I hope you have a great day. Congratulations, and thank you for talking with us, Gov. Weld, here on Morning Edition.