Clinton spoke yesterday night during the Civil Rights Summit at the Lyndon B Johnson Presidential Library at the University of Texas in Austin. The library is hosting the three-day event to mark the anniversary of the landmark 1964 law that banned widespread discrimination against racial and ethnic minorities and women.
President Barack Obama is scheduled to give the keynote address today and former President George W Bush will wrap up the summit later that day.
He also praised those who gave their lives in the civil rights struggle, such as Martin Luther King, Medgar Evers and other victims of bombings and shootings.
Clinton spent much of his speech addressing last year's US Supreme Court ruling that struck down key provisions of the 1965 Voting Rights Act, which was also signed into law by Johnson. The ruling allows several states with a history of discriminatory voting laws, mostly in the south, to change election laws without federal approval.
Also Read
Clinton noted laws in at least 10 states that require voters to present photo identification to cast ballots. "We all know what this is about. This is a way of restricting a franchise after 50 years of expanding it," Clinton said. "Is this was Martin Luther King gave his life for?"
Supporters of the measures, mostly Republican conservatives, contend that the ID checks protect against fraudulent voting and thus help build trust in government. Critics see them as a way of discouraging the kind of voters who lack picture IDs and might be more likely to support Democrats.
Clinton signed the federal Defense of Marriage Act in 1996, which barred federal recognition of same-sex marriages. By 2013, Clinton said he believed the bill to be unconstitutional, arguing that it allowed discrimination. The Supreme Court ruled last year that the law improperly deprived gay couples of due process.