FILE - In this July 10, 2018 file photo, former Trump national security adviser Michael Flynn leaves federal courthouse in Washington, following a status hearing. (AP Photo/Manuel Balce Ceneta)

FILE - In this July 10, 2018 file photo, former Trump national security adviser Michael Flynn leaves federal courthouse in Washington, following a status hearing. (AP Photo/Manuel Balce Ceneta)

FILE - In this Oct. 6, 2018 file photo, Senate Majority Leader Mitch McConnell, R-Ky., finishes speaking to reporters at the Capitol in Washington. McConnell’s blockade of a popular criminal justice reform package has angered top senators. And it’s created an unusual rift with a longtime Republican ally, Sen. Chuck Grassley of Iowa. (AP Photo/J. Scott Applewhite)

In this Dec. 7, 2018 photo, President Donald Trump speaks the 2018 Project Safe Neighborhoods National Conference in Kansas City, Mo. Trump’s growing legal peril has unnerved Republicans who believe the turmoil has left the president increasingly vulnerable as he gears up for what is sure to be a nasty fight for re-election. (AP Photo/Andrew Harnik)

FILE - In this April 21, 2013 file photo, Maria Butina, leader of a pro-gun organization in Russia, speaks to a crowd during a rally in support of legalizing the possession of handguns in Moscow, Russia. Prosecutors say they have “resolved” a case against Butina accused of being a secret agent for the Russian government, a sign that she likely has taken a plea deal. The information was included in a court filing Monday. (AP Photo/File)

U.S. Border Patrol agents stand in front of a secondary fence in San Diego, California looking across border wall toward Mexico as they respond to a group of Central American migrants who crossed the border wall illegally, seen from across the wall in Tijuana, Mexico, Sunday, Dec. 9, 2018. Discouraged by the long wait to apply for asylum through official ports of entry, many Central American migrants from recent caravans are choosing to cross the U.S. border wall illegally and hand themselves in to Border Patrol agents to request asylum. (AP Photo/Rebecca Blackwell)

FILE - In this Sept. 28, 2018, file photo, House Judiciary Committee ranking member Jerry Nadler, D-N.Y., talks to media during a Senate Judiciary Committee hearing on Capitol Hill in Washington. Nadler, the top Democrat on the House Judiciary Committee says he believes it would be an "impeachable offense" if it's proven that President Donald Trump directed illegal hush-money payments to women during the 2016 campaign. But Nadler, who’s expected to chair the panel in January, says it remains to be seen whether that crime alone would justify Congress launching impeachment proceedings. (AP Photo/Carolyn Kaster, File)

FILE - In this June 1, 2017 file photo, protesters gather outside the White House in Washington to protest President Donald Trump's decision to withdraw the Unites States from the Paris climate change accord. Environmental activists are ramping up a pressure campaign aimed at stoking Democratic support for an ambitious environmental plan known as the Green New Deal ahead of the 2020 presidential race. (AP Photo/Susan Walsh)

Pittsburgh Steelers quarterback Ben Roethlisberger (7) passes against the Oakland Raiders during the first half of an NFL football game in Oakland, Calif., Sunday, Dec. 9, 2018. (AP Photo/Ben Margot)