Bernie Sanders' political career

Democratic presidential candidate U.S. Sen. Bernie Sanders (I-VT) delivers remarks while officially announcing his candidacy for the U.S. presidency during an event at Waterfront Park May 26 in Burlington, Vermont.

Bernie Sanders' political career

Sanders participates in a "Don't Trade Our Future" march organized by the group Campaign for America's Future on April 20 in Washington. Click through for other photos from his career.

Bernie Sanders' political career

Sanders speaks to protesters taking part in the "Don't Trade Our Future" march on April 20.

Bernie Sanders' political career

Sanders speaks to low-wage federal contract workers during a protest where the workers demanded presidential action to win a wage increase to $15 an hour on December 4, 2014, in Washington.

Bernie Sanders' political career

Sanders, left, and Sen. Charles Grassley of Iowa arrive with other senators for a briefing at the U.S. Capitol on September 11, 2014, by military and intelligence officials for members of the U.S. Senate on the White House strategy to combat ISIS.

Bernie Sanders' political career

Sanders awaits the start of a hearing on the state of veterans' health care by the Senate Veterans Affairs Committee on September 9, 2014, in Washington.

Bernie Sanders' political career

On September 8, 2014, Sanders speaks outside the U.S. Capitol at a press conference where members of Congress discuss a joint resolution proposing a constitutional amendment relating to contributions and expenditures intended to affect elections.

Bernie Sanders' political career

Then-senator-elect Bernie Sanders meets with 2006 Senate Minority Leader Harry Reid (right) on November 13, 2006, in Washington, D.C. On his left is then-senator-elect James Webb and on his right is then-senator-elect Amy Klobuchar.

Bernie Sanders' political career

Sanders addresses a rally in support of Social Security on March 28, 2011, on Capitol Hill.

Bernie Sanders' political career

Sanders speaks to reporters on Capitol Hill on December 7, 2010, about how the Obama administration is pushing for Congress to extend Bush-era tax cuts in a compromise with Republicans.

Bernie Sanders' political career

Sanders speaks at a news conference in Washington on September 30, 2009, to urge Congress to pass a $250 one-time cost of living adjustment payment to Social Security recipients in 2010.

Bernie Sanders' political career

Sanders speaks during a hearing on the economy before the Senate Budget Committee on Capitol Hill on March 3, 2009.

Bernie Sanders' political career

Incoming Sens. James Webb, from left, Sanders, and Amy Klobuchar meet with Senate Minority Leader Harry Reid on November 13, 2006, in Washington.