Transcript for Trump says he may not alert FBI if info is offered by foreigners on 2020 candidates
But we begin tonight with the exclusive interview just before we came on the air tonight. President trump with our George Stephanopoulos. The president talking about the race for 2020 and those new polls, getting a lot of attention, that show several Democrats ahead of the president in head to head match-ups. Joe Biden with the biggest lead over the president. Tonight, the president saying those polls are untrue, and telling George he has a strong case to make to the American people on why he should be re-elected. And George asking the president, if the Russians, if China have dirt on his opponent this time around, would he entertain it or would he call the FBI? Let's get right to George live at the white house tonight where this interview just wrapped up. George? Reporter: Good evening, David. It was and extraordinary 48 hours. Access like we've never seen before to the president of the United States. On air force one, in the oval office, where the president took on those polls he calls fake. As we walked into the oval office, president trump had already tweeted about new polls showing him behind the clearly not happy. Why does it bother you so much? Because it's untrue. I like the truth. You know, I'm actually a very honest guy. If I thought they were correct, I wouldn't be complaining at all. I understand that. It's like the witch hunt that goes on. Reporter: The Russia investigation. A topic he raised first and returned to again and again. As we spoke in the white house, over on capitol hill, Donald Trump Jr. Was arriving to testify again. Are you here to correct your testimony? Nothing to correct. Reporter: Your son, don Jr., is up before the senate intelligence committee today, and again, he was not charged with anything. In retrospect, though -- Not only wasn't he charged, if you read it, with all of the horrible fake news, I mean, I was reading that my son was going to go to jail. This is a good, young man, that he was going to go to jail. Reporter: In June of 2016, just months before the election, don Jr. Received an email from a business associate promising dirt on Hillary Clinton from the Russian government. Don jr.'s response, "If it's what you say, I love it." The conversation led to a meeting in trump tower that included the president's son, his son-in-law, Jared Kushner and a Russian lawyer. Don Jr. Insists nothing came of it, and special counsel Robert Mueller did not find evidence to charge conspiracy. Then the report comes out and they didn't even say, they hardly even talked about him. Reporter: Should he have gone to the FBI when he got that Okay, let's put yourself in a position. You're a congressman, somebody comes up and says, hey, I have information on your opponent, do you call the FBI? I don't think -- Reporter: If it's coming from Russia, you do. I'll tell you what, I've seen a lot of things over my life. I don't think in my whole life I've ever called the FBI. In my whole life. You don't call the FBI. You throw somebody out of your office, you do whatever you do -- Reporter: Al gore got a stolen briefing book, he called the FBI. Well, that's different, a stolen briefing book, but this is somebody who said, we have information on your opponent. Oh, let me call the FBI, give me a break. Life doesn't work that way. Reporter: The FBI director said that's what should happen. The FBI director is wrong. Reporter: Your campaign this time around, if foreigners, if Russia, if China, if someone else offers you information on opponents, should they accept it or should they call the FBI? I think maybe you do both. I think you might want to listen. I don't -- there's nothing wrong with listening. If somebody called from a country, Norway, we have information on your opponent. Oh. I think I'd want to hear it. Reporter: You want that kind of interference in our elections? It's not interference. They have information. I think I'd take it. If I thought there was something wrong, I'd go maybe to the FBI, if I thought there was something wrong, but when somebody comes up with oppo research, right, they come up with oppo research. Oh, let's call the FBI. The FBI doesn't have enough agents to take care of it. When you go and talk, honestly, to congressmen, they all do it. They always have, and that's the way it is. It's called oppo research. So, let's get back to George tonight. George, it's very clear, the race for 2020 is also on the president's mind, the tweets, already trading attacks with Joe Biden. And he told you he has a strong case to make for reelection. Reporter: He's excited about that case, David. And he's excited about relaunching next Tuesday in Orlando. Says over 70,000 people will attend. He's ready to make that case. But it is also clear, David, that he's angry at the press, angry about those polls and still very concerned and interested in that Russia investigation. All right, incredible access over a couple of days. George Stephanopoulos at the white house tonight. George, thank you. And of course, George will have much more first thing in the morning on "Good morning America," and a primetime special in the coming days, that date and time coming.
This transcript has been automatically generated and may not be 100% accurate.