Transcript for 'Assaults on the Biden family are not relevant to the issues of this case': Booker
And we are joined now by democratic senator Cory booker. He joins us from Iowa this morning. Senator booker, thank you for joining us. I have to start, and I want you to promise. You dropped out of the presidential race. Why are you still in Iowa? I came out here to say thank you to the hundreds and hundreds of folks who helped me in this election. It's just incredible to see the kind of support we had here, and these are the folks we're going to need for the general election, and for elections up and down the ballot. I'm here to say thank you and to let people know that I may not be in this race, but we have to press on in the fight. This is the most consequential election of our lifetimes, and everybody has to get involved even if our top choice candidate is not the nominee. You have just heard you will be serving as a judge and juror in this senate trial. You heard professor Dershowitz and senator Shelby saying that even if everything in the house case is accepted as fact, it's not impeachable. Your response? Honestly that's just stunning to me, and I don't know what signal we're sending to future presidents if that's the new standard in America where you can openly solicit foreign interference, and hold up taxpayer dollars, and it's what the government accountability office says it's illegal to do so, in order to extort, to leverage foreign interference in our elections. This is preposterous that this would not be an impeachable offense, that this standard in America is now that presidents can abuse their power to help them in elections. It's just -- this is unacceptable, and the fact we can't even get Republicans to answer your question directly, is that behavior wrong? It is absolutely wrong, and this is the thing that really disturbs me because we as senators have access to classified information much of actually is in the public sphere about the incredibly detailed, earnest efforts by the Russians and others to interfere in our elections. This is -- this is real from Madagascar to the eu. Democracy is under attack by at least Russia and more countries to try -- to try to undermine democracy as we know it. We have a president that has openly been engaging with the Russians and others. Right now in this case Ukraine to undermine our elections. This is a real threat to this nation, and so what are we going to do when a president openly unabashedly in a way that's proven, and provable in a way his top levels of administration has done? What are we going to do when our democracy is under threat? Tolerate this behavior or do something to stop it and hold that person accountable? One of the biggest questions is whether you will hear from new witnesses. One of the proposals you're seeing floated now is reciprocity, saying the Democrats get the witnesses they're calling for, then the Republicans should get the witnesses they're calling for like hunter Biden. Is that fair? These assaults on the Biden family are not relevant to what's at issue in this case, and this is an invitation to try to muddle waters. It's what we have been hearing from many right-leaning organizations, just trying to muddle the waters. There is a trial going on in the senate about the conduct of the president of the United States and what is the fact that should be presented should be Germain to the issue at hand, and so I'm going to press for what every objective juror should press for, is relevant fact witnesses coming before this senate, and this absurdity again that there are first hand witnesses like Bolton that would not come before the United States senate, that means we won't have the kind of trial that every American should expect where we get to the facts. We get to the relevant information, and can discern the truth. You know, president trump and others have suggested that the Democrats are slow walking this impeachment, and speaker Pelosi upheld the articles in order to help Joe Biden and hurt Bernie Sanders. What do you make of that? As someone who was competing, what impact do you think of the trial for the senators that now have to serve? Look. I worry about this election coming up a lot, and the Republican arguments that just -- let's let the voters decide. It's almost like saying that the Astros have cheated and we're going to decide whether to hold them accountable by how they do in the next game. Our democracy is under attack. It is under ongoing attack. We have a president that is cooperating or leveraging, working with foreign powers to try to undermine the fairness of election. We need to act. We need to act now, and all of us, and I know my senators. You just had a colleague that I am friends with, Richard Shelby. I know the goodness of this country, the decency of folks. This is a moment for us to get out of our partisan corners and look at the long mark of history, and look at the spirit of democracy that's been going on for a couple of centuries plus right now. We are -- the history has its eyes on us. How are we going to operate? We cannot cave to partisanship and tribalism that's destroying our nation. At this moment, we have to let our highest selves come through, and sit in those seats and uphold the oath we all just swore last week, and do right by our nation, to ensure that this democracy endures. Do you expect to endorse another candidate for president on the democratic side before Iowa? I'm not sure. I'm literally still just days from stepping out of this race. The values that I ran for, just what I mentioned are relevant to this impeachment trial. We are a nation that has to come back together. The lines that divide us, I don't care what our TV stations tell us, the cable news, the lines that divide us are not as strong as the ties that bond us. The greatest threat I see right now is we can't even make our civic spaces reflect the things we agree on. We agree on common sense gun safety, and infrastructure, and so many things we agree on that we can't get done anymore, and our competitor nations. Heck, China has just built 18,000 miles of high speed rail, and the busiest rail in our nation, going from Boston to Washington, D.C. Runs a half hour slower than it did in the 1960s. Our ability to come together and stand together as a nation is undermining our competitiveness. I want to support a candidate that wants to send Mitch Mcconnell to the back benches and beat Donald Trump, but understand that beating Donald Trump is the floor, and not the ceiling. It may get us out of a terrible valley, but we're called as a nation to go towards the mountain top, and I'm going to think hard about how to endorse, and whoever wins has to be able to heal this nation. Remind us that the call of every generation of Americans is to put more indivisible into this one nation under god. Senator booker, thank you for your time. Thank you.
This transcript has been automatically generated and may not be 100% accurate.