Transcript for FBI Director James Comey to testify before Congress
occupant, president trump is headed into a high-stakes week. Tomorrow, James Comey, the FBI director, will publicly answer questions about the president's wiretapping qulams. And Russia's alleged meddling in the presidential election. This morning, president trump remaining in west palm beach. That's where we find David Wright. Reporter: Good morning, Paula. Just to remind everybody, James Comey, the guy set to testify tomorrow is the same guy behind that on again off again investigation of Hillary Clinton's private e-mail server. He had a big influence on the election. He's back again. The this time, the house intelligence committee. The to big topics, Russia and wiretapping. Is the truth, the whole truth, and nothing but the truth. Reporter: As the nation's most powerful law enfoermt officer, FBI director James comb Ya is in a position to know whether there's any credible evidence to support either story. One, advanced by trump's critics that representatives of trump's campaign may have colluded with yush Ya to help him win the election. And the other by trump himself, that president Obama bugged trump tower. Have you seen any evidence? Reporter: Last week, Comey briefed senators behind closed doors. This briefing was all on sensitive matters. Highly classified. It's not anything we we can answer questions about. Reporter: A statement was released saying there was no indication that trump tower was the subject of Su valance by any element of the United States government before or after election day 2016. That didn't stop trump from joking about it with German chancellor Angela Merkel at the white house Friday. At least we have something in common, perhaps. Reporter: Comey's testimony tomorrow has the potential to be equally double-edged. His standing with the white house on the line. Also on the hill Monday, supreme court nominee Neil Gorsuch. He's the man of our country and man who our country really needs and needs badly to ensure the rule of law and the rule of justice. Reporter: Trump's nominee to replace justice Antonin Scalia. A year after president Obama introduced his nominee to the post, Merrick Garland. A big news day tomorrow. Comey has made it clear privately that there's no truth, so far as he nose, to the wiretapping claim. President trump has not attacked him. That could change depending on what he says tomorrow. David, as you said, a huge news day. Let's bring in George Stephanopoulos who will be hosting "This week" later this morning. What's at stake with this hearing tomorrow? The president's credibility. Flat out. He's made this claim two weeks ago. 15 days ago. He was illegally wire-tapped by president Obama. That not true. It's false. He's not been told that by his attorney general, the CIA director,director of national intelligence. We know, as David said, that director Comey has privately told the justice department he has no evidence of that. What will Comey say publicly? If he does, the next question is how is the president going to respond? Will he finally back down? Apologize for his statement? Will he take off on Comey? Will he fire Comey? We don't know at this point what the president will do in the face of all the evidence of the last 15 days, he's not backed down. So much intrigue. We also mentioned the supreme court hearings for Neil Gorsuch begins tomorrow. Do you think Democrats will be aggressive? I think they'll ask a lot of aggress i6 questions. In the end, how many Democrats will vote for him? In the end, I don't think it will be a matter. Even if Democrats are united in opposition, the Republicans have made it very, very clear that they will change the rules and allow him to be passed by a majority of a 51 senators. And there are enough Republicans to do that in the Democrats maintain the op vision zigs. Democrats will be raising questions. What we're going to watch for is whether some of those Democrats say, you know what? He's about as good as we're going to do. He's qualified for the job, we'll vote for him. The other big event this week that we mention sd Thursday's vote on repealing and replacing Obamacare. This is in the house. It still has to go to the senate. What's in play? It's still in flux. There has been trouble getting votes so far. President trump has brought in several reluctant conservatives. It doesn't appear yet that the majority is there. We'll see if they can get it. They probably won't schedule a vote until they have a majority. The changes that are going to required to get the bill through the house are likely to cause the bill more trouble in the senate, where many senator, more than a dozen, have raised questions. Three are opposed. Many senators saying is house bill, etch if it passes this week, is dead on arrival. George Stephanopoulos, great to have you here. I Wacht to remind even. George has a big show this morning. He'll go one on one with health and human services head Tom price. And Rand Paul. He'll talk to two key committee members. All coming up on "This week" on ABC.
This transcript has been automatically generated and may not be 100% accurate.