WASHINGTON, DC - SEPTEMBER 06: U.S. Sens. Cory Booker (D-NJ) and Debbie Stabenow (D-MI) head for a vote at the U.S. Capitol September 6, 2016 in Washington, DC. Congress returned from a seven-week break and was scheduled to take up legislation related to the Zika virus outbreak, continued funding for the federal government and other matters. (Photo by Chip Somodevilla/Getty Images)

WASHINGTON, DC - SEPTEMBER 06: U.S. Sen. John McCain (R-AZ) is pursued by reporters as he heads for a vote at the U.S. Capitol September 6, 2016 in Washington, DC. Congress returned from a seven-week break and was scheduled to take up legislation related to the Zika virus outbreak, continued funding for the federal government and other matters. (Photo by Chip Somodevilla/Getty Images)

WASHINGTON, DC - SEPTEMBER 06: U.S. Sen. Barbara Mikulski (D-MD) (C) talks to reporers as she heads for a vote at the U.S. Capitol September 6, 2016 in Washington, DC. Congress returned from a seven-week break and was scheduled to take up legislation related to the Zika virus outbreak, continued funding for the federal government and other matters. (Photo by Chip Somodevilla/Getty Images)

WASHINGTON, DC - SEPTEMBER 06: U.S. Sen. Elizabeth Warren (D-MA) (C) talks with staffers as she heads for a vote at the U.S. Capitol September 6, 2016 in Washington, DC. Congress returned from a seven-week break and was scheduled to take up legislation related to the Zika virus outbreak, continued funding for the federal government and other matters. (Photo by Chip Somodevilla/Getty Images)

WASHINGTON, DC - SEPTEMBER 06: U.S. Sen. Elizabeth Warren (D-MA) (2nd R) talks with staffers as she heads for a vote at the U.S. Capitol September 6, 2016 in Washington, DC. Congress returned from a seven-week break and was scheduled to take up legislation related to the Zika virus outbreak, continued funding for the federal government and other matters. (Photo by Chip Somodevilla/Getty Images)

WASHINGTON, DC - SEPTEMBER 06: Speaker of the House Paul Ryan (R) (R-WI) is escorted by members of his security detail while leaving his office at the U.S. Capitol September 6, 2016 in Washington, DC. Congress returned from a seven-week break today and are expected to take up legislation related to the Zika virus outbreak, continued funding for the federal government and other matters. (Photo by Win McNamee/Getty Images)

WASHINGTON, DC - SEPTEMBER 06: House Majority Leader Kevin McCarthy (R) (R-CA) leaves the office of Speaker of the House Paul Ryan at the U.S. Capitol September 6, 2016 in Washington, DC. Congress returned from a seven-week break today and are expected to take up legislation related to the Zika virus outbreak, continued funding for the federal government and other matters. (Photo by Win McNamee/Getty Images)

WASHINGTON, DC - SEPTEMBER 06: U.S. Senate Majority Leader Mitch McConnell (R-KY) (R) walks back to his office with Senate Republican Secretary Laura Dove at the U.S. Capitol September 6, 2016 in Washington, DC. Congress returned from a seven-week break and will take up legislation related to the Zika virus outbreak, continued funding for the federal government and other matters. (Photo by Chip Somodevilla/Getty Images)