SELMA, Ala. (AP) – Several Democratic White House hopefuls gathered at one of America’s seminal civil rights sites on Sunday to pay homage to that legacy and highlight their own connections to the movement.

Sens. Cory Booker of New Jersey and Bernie Sanders of Vermont, who already are in the 2020 race, and Sen. Sherrod Brown of Ohio, who could soon join them, attended a unity breakfast to commemorate “Bloody Sunday” in Selma, Alabama. Also on hand for events was Hillary Clinton, the party’s nominee in 2016.

On March 7, 1965, Alabama state troopers beat peaceful demonstrators as they attempted to cross the Edmund Pettus Bridge. It was a moment that galvanized support for the passage of the Voting Rights Act later that year.

This year’s commemoration came in the early days of a Democratic primary that has focused heavily on issues of race. Several candidates have called out President Donald Trump as a racist while others have voiced support for the idea of reparations for the descendants of enslaved black Americans.

Booker, who announced his candidacy at the start of Black History Month, said in the keynote address at Brown Chapel AME Church that the “Bloody Sunday” anniversary was a time to recommit to the fight for justice in America.

“It’s time for us to defend the dream,” the New Jersey Democrat said at the church, which was the starting point of the 1965 march. “It’s time that we dare to dream again in America. That is what it takes to make America great. It is up to us to do the work that makes the dream real.” Booker has cast himself as a direct beneficiary of the civil rights era after his family was denied housing in a white neighborhood. In January, he traveled through Georgia with Rep. John Lewis, D-Ga., an Alabama native and civil rights leader who was severely beaten at the bridge 54 years ago.

Other candidates visiting Selma have highlighted in the past how civil rights shaped their narratives.

Brown, currently on a “Dignity of Work” tour inspired by King, returned to Selma for the fifth time. He frequently draws connections between civil rights and worker’s rights. A former secretary of state in Ohio, Brown also has a reputation as a leader on expanding voter participation.

Sanders attended the 1963 March on Washington, which featured the Rev. Martin Luther King Jr.’s “I Have A Dream” speech. The Vermont senator has highlighted his civil rights and activist background as a young man at the University of Chicago. He is working to reset his relationship with black voters, with whom he struggled to connect in the 2016 Democratic primary that Clinton won.

Clinton told those at Brown Chapel that the absence of crucial parts of the Voting Rights Act contributed to her 2016 loss to Trump. The Supreme Court in 2013 struck down a part of the law that required the Justice Department to scrutinize states with a history of racial discrimination in voting. Congress has yet to address the issue.

Clinton said “it makes a really big difference” and warned of the need for continued vigilance about voter suppression heading into the 2020 election.

The backdrop of Selma provides a spotlight on voting rights. Advocates say the gains achieved as a result of “Bloody Sunday” have been threatened in recent years, particularly by the 2013 Supreme Court decision.

Voter suppression emerged as a key issue in the 2018 midterm elections in states such as Georgia and North Carolina, where a Republican congressional candidate was accused of rigging the contest there through absentee ballots. House Democrats signaled they plan to make ballot access a priority in the new Congress, introducing legislation aimed at protecting voting rights in 2020 and beyond.