Transcript for Rep. Nancy Pelosi makes triumphant return to power

But we're going to begin with that historic power shift in Washington. Democrats taking over the house and making history, with the new makeup of congress. Nancy Pelosi, the first woman to ever be speaker of the house, now returning for her second run in the role. Calling the session to order with her grandchildren, inviting all of the children and grandchildren in the chamber right up to the podium. Calling it a new dawn, Pelosi welcomed the most diverse group of representatives the congress has ever seen. And in a surprise move late today, president trump appearing in the white house briefing room with his own message for speaker Pelosi. And a reminder tonight, despite the pa generality we saw today, it is now day 13 of the government shutdown. 800,000 Americans are waiting to get paid. Many others won't even get back pay. Mary Bruce leads us off from the hill tonight. Reporter: With her grandchildren by her side, a beaming Nancy Pelosi made a triumphant return to power. The next speaker of the United States house of representatives. Reporter: With the passing of the gavel, president trump for the first time faces a divided congress. Two months ago, the American people spoke and demanded a new dawn. They called upon the beauty of our constitution, our system of checks and balances that protects our democracy. Reporter: Pelosi herself making history for the second time. I am particularly proud to be the woman speaker of the house of this congress, which marks 100th year of women having the right to vote. Reporter: And there are now 102 women in congress, more than ever before. Among them, the youngest female member, New York Democrat Alexandria ocasio-cortez. Their diversity also historic. The first muslim-american congresswomen, Democrats Rashida tlaib whose mother held Thomas Jefferson's Koran, and ilhan OMAR, who came to the U.S. 23 years ago as a refugee from Somalia. Pelosi invoking Ronald Reagan to send a pointed message on immigration. He said, if we ever close the door to new Americans, our leadership role in the world will soon be lost. Ronald Reagan. No applause for Ronald Reagan? Reporter: Then, she summoned her grandchildren to the podium. Do what we've all been waiting for. I now call the house to order on behalf of all of America's children. Reporter: Pelosi takes power on day 13 of the government shutdown, but at the white house, in an impromtu visit to the briefing room, warm words from president trump. I just want to start off by congratulating Nancy Pelosi on being elected speaker of the house. It's a very, very great achievement, and hopefully we're going to work together and we're going to get lots of things done, like infrastructure and so much more. Reporter: But the battle lines are already drawn. Congressional Democrats, now armed with subpoena power, are preparing to investigate all aspects of the president's administration and campaign. And Pelosi's not ruling out that trump could be indicted while still in office. I think that that is an open discussion. I think that's an open discussion in terms of the law. Let's get to Mary Bruce, watching this all unfold today with us. A lot of Americans also watching history play out, but likely asking, when are you going to get the government back open? 800,000 workers waiting to be paid. Many others won't get back pay. And another meeting now set at the white house for tomorrow? Reporter: Yes, but David, so far, talks are going nowhere. And today, the president is again digging in, insisting he will build his wall, even though Democrats say that's simply not going to happen. Despite all this, the two sides are going to sit down at the white house tomorrow and go another round. David? Mary Bruce leading us off, thank you, Mary.

This transcript has been automatically generated and may not be 100% accurate.