President Donald Trump, flanked by Vice President Mike Pence and Chief of Staff Reince Priebus, signs his first executive order on health care, Friday, January 20, in the Oval Office of the White House in Washington. Evan Vucci/AP

President Donald Trump smiles with his son Barron as they watch the 58th Presidential Inaugural Parade in Washington on Friday, January 20. Pablo Martinez Monsivais/AP

President Donald Trump salutes members of the New York Military Academy during the 58th Presidential Inaugural Parade on Friday, January 20. Pablo Martinez Monsivais/AP

President Donald Trump and Vice President Mike Pence salute military personnel from the main reviewing stand in front of the White House during the Presidential Inaugural Parade. Patrick Smith/Getty Images

President Donald Trump steps out of his limousine in front of the Presidential Inaugural Parade reviewing stand on Pennsylvania Avenue on Friday, January 20. Andrew Harnik/AP

Vice President Mike Pence, center, waves to supporters as he walks with his family during the Presidential Inaugural Parade. Joe Raedle/Getty Images

Spectators watch from rooftops as President Donald Trump and first lady Melania Trump walk in the inaugural parade on Friday, January 20, in Washington. Kevin Dietsch/Pool/Getty Images

President Donald Trump waves as he walks on Pennsylvania Avenue with first lady Melania Trump during the Presidential Inaugural Parade on Friday, January 20. Evan Vucci/AP

The U.S. Army Old Guard Fife and Drum Corps marches in the Presidential Inaugural Parade on Friday, January 20, in Washington. Joe Raedle/Getty Images

Secret Service members surround the presidential limousine as it drives up Pennsylvania Avenue during the Presidential Inaugural Parade on Friday, January 20, in Washington. JIM WATSON/AFP/Getty Images

Police escorts participate in the Presidential Inaugural Parade procession on January 20, in Washington. Chip Somodevilla/Getty Images

From left, first lady Melania Trump, President Donald Trump, US Army Maj. Gen. Bradley Becker, Vice President Mike Pence and Karen Pence review the troops as part of the inaugural ceremonies. ROBYN BECK/AFP/Getty Images

Members of a military band line up prior to marching in the Presidential Inaugural Parade. Patrick Smith/Getty Images

President Trump waves to Hillary Clinton, whom he defeated in the election, during his speech at the inaugural luncheon. He was sworn in as the 45th President of the United States on Friday, January 20. Manuel Balce Ceneta/AP

Dignitaries bow their heads in prayer during the inaugural luncheon. Aaron P. Bernstein/Getty Images

Newly sworn in President Trump shakes hands with Hillary Clinton. Manuel Balce Ceneta/AP

President Trump is joined by the congressional leadership and his family as he formally signs his cabinet nominations into law. J. Scott Applewhite/AP

Former President Barack Obama waves as he boards a Marine helicopter during a departure ceremony. Evan Vucci/AP

The Obamas and Trumps walk to Marine One after Donald Trump was sworn in as President. John Angelilo/Pool/Getty Images

President Trump delivers his inaugural address after being sworn in as the 45th President of the United States on Friday, January 20. Patrick Semansky/AP

Trump is sworn in as President with his wife, Melania, at his side. Andrew Harnik/AP

Supporters watch as Trump appears for his inauguration. John Minchillo/AP

Vice President Mike Pence is sworn in by Justice Clarence Thomas as Pence's wife, Karen, holds the bible. Andrew Harnik/AP

Trump arrives on the West Front of the Capitol to be sworn in. Scott Olson/Getty Images

President Barack Obama chats with Trump before the ceremony. Chip Somodevilla/Getty Images

Trump arrives on the West Front of the Capitol. Alex Wong/Getty Images

Trump waits to step out onto the portico for his presidential inauguration. Patrick Semansky/AP

Pence arrives at the Capitol for the inauguration. SAUL LOEB/AFP/Getty Images

Obama and Vice President Joe Biden arrive on the West Front of the Capitol. Senate Minority Leader Chuck Schumer and House Minority Leader Nancy Pelosi step before them. Alex Wong/Getty Images

Melania Trump arrives for the ceremony. SAUL LOEB/AFP/Getty Images

Former President Jimmy Carter, Rosalynn Carter, former President Bill Clinton, Hillary Clinton, former President George W. Bush and Laura Bush wait for the ceremony to begin. Andrew Harnik/AP

Trump's children look for their seats before the ceremony begins. Susan Walsh/AP

Supreme Court justices await the ceremony. Front from left: Chief Justice John Roberts and Justices Anthony Kennedy and Clarence Thomas. Back from left: Justices Ruth Bader Ginsburg, Sonia Sotomayor, Stephen Breyer and Samuel Alito. PAUL J. RICHARDS/AFP/Getty Images

Crowds file in along the National Mall before Trump's swearing-in. Patrick Semansky/AP

Former House Speakers Newt Gingrich and John Boehner arrive with their wives at the Capitol. Alex Wong/Getty Images

Former Vice President Dick Cheney arrives for the inauguration. Win McNamee/Getty Images

Sen. Ted Cruz arrives for the ceremony. SAUL LOEB/AFP/Getty Images

Sen. Bernie Sanders waves to the crowd from the West Front of the Capitol before the ceremony. Chip Somodevilla/Getty Images

The presidential motorcade moves down Pennsylvania Avenue to the Capitol for the inauguration ceremony. Cliff Owen/AP

Former Vice President Dan Quayle and his wife, Marilyn, arrive for the ceremony. Saul Loeb/Pool/Getty Images

The Obamas welcome the Trumps to the White House as they arrive for inauguration festivities Mark Wilson/Getty Images

President Obama kisses the first lady as they await the arrival of President-elect Trump and his wife, Melania. Evan Vucci/AP

Pence arrives for a worship service at St. John's Episcopal Church across from the White House. Alex Brandon/AP

The Rev. Luis Leon greets the Trumps on their arrival for the service at St. John's. Alex Brandon/AP

The rain doesn't deter a crowd from gathering to watch the inauguration ceremony. MARK RALSTON/AFP/Getty Images

Workers dry seats on the West Front of the US Capitol. Scott Olson/Getty Images

Vice President Joe Biden and his wife, Jill, prepare to leave the White House for the final time. Kevin Dietsch/Pool/Getty Images