Thousands of demonstrators streamed down Martin Luther King Jr. Drive chanting, singing and marching on Saturday in support of extending the 40-year-old Voting Rights Act.

Organizers hope the "Keep the Vote Alive" march will pressure Congress and President Bush to extend key provisions of the landmark law, which expires in 2007.

"Forty years later, we're still marching for the right to vote," said U.S. Rep. John Lewis (search), who participated in the civil rights struggles that helped secure passage of the law in 1965. "Don't give up, don't give in. Keep the faith, keep your eyes on the prize."

Activists from across the country joined Lewis, NAACP (search) President Bruce Gordon and the Rev. Jesse Jackson (search), who heads the Rainbow/PUSH Coalition, at Saturday's demonstration.

"The right to vote does not endanger, but we must protect it against discrimination," Jackson said at a rally at the end of the march.

Civil rights groups fear conservatives will try to modify two key provisions of the law. One requires nine states, mostly in the South, to get federal approval before changing voting rules. The other requires election officials to provide voting material in the native language of immigrant voters who don't speak English.

Activists also used the rally to protest Georgia's recently passed voter identification law, which critics call the most restrictive in the country.

If that bill is approved by the Department of Justice (search), Jackson warned on Friday, it could "spread like a virus" to other states. Rainbow/PUSH is among a list of objectors that have urged the Department of Justice not to approve the law.

In the weekly Democratic radio address, Lewis said his party is committed to strengthening the sections of the law that are set to expire.

"Our democracy depends on protecting the right of every American citizen to vote in every election," Lewis said.