WASHINGTON, DC - SEPTEMBER 13: U.S. Sen. Bernie Sanders (I-VT) (R) speaks during a rally against the Dakota Access Pipeline September 13, 2016 at Lafayette Square in Washington, DC. Activists held a rally calling on President Barack Obama to stop the Dakota Access Pipeline. (Photo by Alex Wong/Getty Images)

WASHINGTON, DC - SEPTEMBER 13: Dennis Zotigh (R) and his father Ralph Zotigh (L) of the Kiowa, Dakota, and Pueblo Tribes sing during a rally against the Dakota Access Pipeline September 13, 2016 at Lafayette Square in Washington, DC. Activists held a rally calling on President Barack Obama to stop the Dakota Access Pipeline. (Photo by Alex Wong/Getty Images)

WASHINGTON, DC - SEPTEMBER 13: U.S. Sen. Bernie Sanders (I-VT) (L) waits to be introduced during a rally against the Dakota Access Pipeline September 13, 2016 at Lafayette Square in Washington, DC. Activists held a rally calling on President Barack Obama to stop the Dakota Access Pipeline. (Photo by Alex Wong/Getty Images)

WASHINGTON, DC - SEPTEMBER 13: U.S. Sen. Bernie Sanders (I-VT) speaks during a rally against the Dakota Access Pipeline September 13, 2016 at Lafayette Square in Washington, DC. Activists held a rally calling on President Barack Obama to stop the Dakota Access Pipeline. (Photo by Alex Wong/Getty Images)

U.S. President Barack Obama meets with Israeli Prime Minister Benjamin Netanyahu in the Oval office of the White House in Washington November 9, 2015. REUTERS/Kevin Lamarque

WASHINGTON, DC - SEPTEMBER 13: U.S. Sen. Bernie Sanders (I-VT) (R) speaks during a rally against the Dakota Access Pipeline September 13, 2016 at Lafayette Square in Washington, DC. Activists held a rally calling on President Barack Obama to stop the Dakota Access Pipeline. (Photo by Alex Wong/Getty Images)

U.S. President Barack Obama speaks during a meeting with the congressional leadership at the Oval Office of the White House, in Washington U.S., September 12, 2016. REUTERS/Carlos Barria

WASHINGTON, DC - SEPTEMBER 13: Sen. Charles Schumer (D-NY) listens to Senate Minority Leader Harry Reid (D-NV) talk to reporters following the weekly Senate Democratic policy luncheon at the U.S. Capitol September 13, 2016 in Washington, DC. Reid repeated the Democrats' call on the Senate Republicans in the majority to allow a vote for funding to fight against the Zika virus and to pass a federal budget continuing resolution. (Photo by Chip Somodevilla/Getty Images)