Civil rights leader John Lewis on Thursday dismissed Democratic presidential candidate Bernie Sanders' 1960s work on racial equality, saying, 'I never saw him. I never met him.'

The Georgia congressman — a stalwart of the Freedom Rides through the South, lunch counter sit-ins and the 1963 March on Washington — raised questions about Sanders' involvement in the movement when the Vermont senator was a college student.

Lewis has endorsed Sanders' chief rival, Hillary Clinton, and his comments come at a critical time as the two White House contenders focus on the upcoming primaries in Southern states with predominantly African-American Democratic voters.

He made the remarks at a Capitol Hill news conference where members of the Congressional Black Caucus' political action committee delivered a full-throated endorsement of Clinton.

All in for Hillary: John Lewis attacked Bernie Sanders as the Congressional Black Caucus endorsed Clinton - and used the press conference to savage the Vermont senator's civil rights record

Battle for black support: Bernie Sanders went to Harlem, New York, on the morning after his New Hampshire victory, to meet the Reverend Al Sharpton for talks with the powerbroker. Sharpton has endorsed neither candidate

On his campaign website, Sanders says he has a 'long history of fighting for social equality and the rights of black Americans — a record that goes back to the early 1960s.'

While a student at the University of Chicago, Sanders was involved in the Congress on Racial Equality and the Student Nonviolent Coordinating Committee. He also was arrested while protesting segregation.

'I never saw him. I never met him,' Lewis told reporters. 'I chaired the Student Nonviolent Coordinating Committee for three years from 1963 to 1966.

'I was involved in the sit-ins, the Freedom Rides, the March on Washington, the march from Selma [Alabama] to Montgomery and directed the voter education project for six years. I met Hillary Clinton, I met President Clinton.'

After routing Clinton in New Hampshire by double digits, Sanders met with the Reverend Al Sharpton in Harlem on Wednesday as the two candidates focus on the more diverse electorate of Nevada, South Carolina and the multiple states holding primaries and caucuses in March.

If Clinton solidifies her support among black voters over the next month, she could amass a significant number of delegates in the push toward the 2,382 needed to win the nomination.

Comeback: Securing black votes could help Clinton amass a significant number of delegates in the push toward the 2,382 needed to win the nomination

There are more than 1,400 delegates at stake in states such as South Carolina, Georgia, Alabama, Tennessee and Louisiana, and depending on the outcome and proportional allocation of delegates, Clinton could build a comfortable lead.

Wins also could drive superdelegates to her candidacy. She currently leads among those elected leaders and party officials, 362-8.

Lewis and other members of the Congressional Black Caucus said they would fan out in the coming days to campaign for Clinton in South Carolina and other states.

Rep. Gregory Meeks, D-N.Y., said the PAC board voted overwhelmingly for Clinton. He said she has been 'our partner long-term,' and would help elect Democrats across the board.

Privately, Democrats fear that Sanders as the nominee would lead to major losses in House and Senate races.

In a swipe at Sanders, Rep. G.K. Butterfield, D-N.C., chairman of the Congressional Black Caucus, said the country needs a president 'who doesn't simply campaign and promise wonderful things, things that are politically impossible to achieve.'

Sanders has called for tuition-free college and government-provided health care for all Americans.