see more

MYRTLE BEACH, SC - FEBRUARY 25: U.S. Democratic presidential candidate Hillary Clinton arrives for a rally February 25, 2016 in Myrtle Beach, South Carolina. The Democratic primary in South Carolina is Saturday. (Photo by Win McNamee/Getty Images)

MYRTLE BEACH, SC - FEBRUARY 25:  U.S. Democratic presidential candidate Hillary Clinton arrives for a rally February 25, 2016 in Myrtle Beach, South Carolina. The Democratic primary in South Carolina is Saturday.  (Photo by Win McNamee/Getty Images)

see more

WASHINGTON, DC - SEPTEMBER 27: Committee chairman Sen. Ron Johnson (R-WI) speaks during a hearing before the Senate Homeland Security and Government Affairs Committee September 27, 2016 on Capitol Hill in Washington, DC. The committee held a hearing on "Fifteen Years After 9/11: Threats to the Homeland." (Photo by Alex Wong/Getty Images)

WASHINGTON, DC - SEPTEMBER 27:  Committee chairman Sen. Ron Johnson (R-WI) speaks during a hearing before the Senate Homeland Security and Government Affairs Committee September 27, 2016 on Capitol Hill in Washington, DC. The committee held a hearing on "Fifteen Years After 9/11: Threats to the Homeland."  (Photo by Alex Wong/Getty Images)

see more

SALINAS, CA - MAY 25: Democratic presidential candidate former Secretary of State Hillary Clinton looks on during a campaign rally at Hartnell College on May 25, 2016 in Salinas, California. Hillary Clinton is campaigning in California ahaed of the State's presidential primary on June 7th. (Photo by Justin Sullivan/Getty Images)

SALINAS, CA - MAY 25:  Democratic presidential candidate former Secretary of State Hillary Clinton looks on during a campaign rally at Hartnell College on May 25, 2016 in Salinas, California. Hillary Clinton is campaigning in California ahaed of the State's presidential primary on June 7th.  (Photo by Justin Sullivan/Getty Images)

see more

Senator Ron Johnson, a Republican from Wisconsin and chairman of the Senate Homeland Security Committee, makes an opening statement during a hearing in Washington, D.C., U.S., on Wednesday, Sept. 27, 2017. Acting Homeland Security Secretary Elaine Duke, FBI Director Christopher Wray, and Nicholas Rasmussen, director of the National Counterterrorism Center, testified on threats to the U.S. Photographer: Andrew Harrer/Bloomberg via Getty Images

Senator Ron Johnson, a Republican from Wisconsin and chairman of the Senate Homeland Security Committee, makes an opening statement during a hearing in Washington, D.C., U.S., on Wednesday, Sept. 27, 2017. Acting Homeland Security Secretary Elaine Duke, FBI Director Christopher Wray, and Nicholas Rasmussen, director of the National Counterterrorism Center, testified on threats to the U.S. Photographer: Andrew Harrer/Bloomberg via Getty Images

see more

LOS ANGELES, CA - DECEMBER 15: Former First Lady of the United States, Hillary Clinton speaks onstage during the LA Promise Fund's Girls Build Leadership Summit held at Los Angeles Convention Center on December 15, 2017 in Los Angeles, California. (Photo by Michael Tran/FilmMagic)

LOS ANGELES, CA - DECEMBER 15:  Former First Lady of the United States, Hillary Clinton speaks onstage during the LA Promise Fund's Girls Build Leadership Summit held at Los Angeles Convention Center on December 15, 2017 in Los Angeles, California.  (Photo by Michael Tran/FilmMagic)