WASHINGTON, DC - SEPTEMBER 21: Speaker of the House Paul Ryan (R) (R-WI) and Sen. Chuck Schumer (L) (D-NY) confer during the ÒFirst Nail CeremonyÓ September 21, 2016 outside the U.S. Capitol in Washington, DC. The ceremony marked the official launch of construction on the Inaugural platform where the next President of the United States will take the oath of office on Friday, January 20, 2017. (Photo by Win McNamee/Getty Images)

WASHINGTON, DC - SEPTEMBER 21: Internal Revenue Service Commissioner John Koskinen testifies before the House Judiciary Committee in the Rayburn House Office Building on Capitol Hill September 21, 2016 in Washington, DC. Despite the lack of evidence against him, Koskinen is facing impeachment threats from conservatives in the House of Representatives for his role in the destruction of computer backups containing thousands of emails sought by Congress in its investigation of political targeting. (Photo by Chip Somodevilla/Getty Images)

WASHINGTON, DC - SEPTEMBER 21: Internal Revenue Service Commissioner John Koskinen testifies before the House Judiciary Committee in the Rayburn House Office Building on Capitol Hill September 21, 2016 in Washington, DC. Despite the lack of evidence against him, Koskinen is facing impeachment threats from conservatives in the House of Representatives for his role in the destruction of computer backups containing thousands of emails sought by Congress in its investigation of political targeting. (Photo by Chip Somodevilla/Getty Images)

WASHINGTON, DC - SEPTEMBER 21: Internal Revenue Service Commissioner John Koskinen testifies before the House Judiciary Committee in the Rayburn House Office Building on Capitol Hill September 21, 2016 in Washington, DC. Despite the lack of evidence against him, Koskinen is facing impeachment threats from conservatives in the House of Representatives for his role in the destruction of computer backups containing thousands of emails sought by Congress in its investigation of political targeting. (Photo by Chip Somodevilla/Getty Images)

WASHINGTON, DC - SEPTEMBER 21: Internal Revenue Service Commissioner John Koskinen testifies before the House Judiciary Committee in the Rayburn House Office Building on Capitol Hill September 21, 2016 in Washington, DC. Despite the lack of evidence against him, Koskinen is facing impeachment threats from conservatives in the House of Representatives for his role in the destruction of computer backups containing thousands of emails sought by Congress in its investigation of political targeting. (Photo by Chip Somodevilla/Getty Images)

WASHINGTON, DC - SEPTEMBER 21: (L-R) Senate Majority Leader Mitch McConnell (R-KY), Sen. Chuck Schumer (D-NY), Speaker of the House Paul Ryan (R-WI), House Majority Leader Kevin McCarthy (R-CA) and House Minority Leader Nancy Pelosi (D-CA) drive nails into a piece of lumber at the ÒFirst Nail CeremonyÓ September 21, 2016 outside the U.S. Capitol in Washington, DC. The ceremony marked the official launch of construction on the Inaugural platform where the next President of the United States will take the oath of office on Friday, January 20, 2017. (Photo by Win McNamee/Getty Images)

Republican vice presidential nominee Mike Pence holds a joint news conference with U.S. House Speaker Paul Ryan (R-WI) (not pictured) following a House Republican party conference meeting in Washington, U.S. September 13, 2016. REUTERS/Jonathan Ernst

WASHINGTON, DC - SEPTEMBER 21: Internal Revenue Service Commissioner John Koskinen arrives for a hearing of the House Judiciary Committee in the Rayburn House Office Building on Capitol Hill September 21, 2016 in Washington, DC. Despite the lack of evidence against him, Koskinen is facing impeachment threats from conservatives in the House of Representatives for his role in the destruction of computer backups containing thousands of emails sought by Congress in its investigation of political targeting. (Photo by Chip Somodevilla/Getty Images)