MURFREESBORO (AP) – Fifty years after the Voting Rights Act was signed into law, two legends of the civil rights movement say they're encouraged by efforts to maintain equality at the polls despite what they see as attempts to thwart it.

The Rev. James Lawson and the Rev. C.T. Vivian are scheduled to speak Thursday at Middle Tennessee State University about the challenges that remain a half-century after the landmark law was signed.

The men, who were friends and confidants of the Rev. Martin Luther King Jr. and led demonstrations that helped make the Voting Rights Act a reality, spoke to The Associated Press ahead of the event.

Vivian, whose civil rights work stretches back nearly seven decades, staged his first sit-in demonstrations in the 1940s. He met King soon after the budding civil rights leader's victory in the 1955 Montgomery Bus Boycott. Vivian's assault during a voting rights demonstration in Selma, Alabama, in 1965 spurred support for the voting rights legislation that was signed the following August.

He said an ongoing battle by a group of Tennessee college students illustrates that the fight is far from over. The students want a federal court to require the state to accept their school identification cards as valid voter identification.

The out-of-state students at Fisk University and Tennessee State University say in a lawsuit that they want to vote in Tennessee but lack proper ID because of voter identification legislation passed by the Tennessee Legislature in 2011. Tennessee won't accept identification cards from other states, nor will it accept student identification cards from Tennessee colleges and universities.

Vivian, 91, said "it's a shame" that such battles still have to be fought, but he's encouraged by the determination of those involved â?? especially young people.

"It lets me know that we will eventually overcome," said Vivian. "And that ... the work we've done for this nation is slowly being fulfilled."

Lawson, 86, who trained students in nonviolent protest in the early 1960s, said, "I support every resistance movement."

Sit-ins by the students Lawson trained led to the successful integration of lunch counters in Nashville, the first of many Southern cities to make that move.

"We are still a society trying to reach the place where we recognize the right of every citizen to vote," he said.

More than two dozen states have passed tougher voting laws over the last several years, adding new requirements on voter ID for instance. In 2013 the U.S. Supreme Court threw out a key section of the Voting Rights Act, requiring all or parts of 15 states with a history of discrimination in voting to get federal approval before changing the way they hold elections. Many have called that requirement the most powerful part of the law.

Chief Justice John Roberts said the provision was outdated, and failed to account for racial progress in U.S. society.

Since then, President Barack Obama and congressional Democrats have called for legislation to strengthen the Voting Rights Act, but they have met with resistance in the GOP-led Congress.

Sponsors of Tennessee's voter ID law wouldn't comment about the students' lawsuit because of the ongoing litigation. They have said previously that requiring voter identification ensures the integrity of the vote and prevents fraud.

But voting rights advocates believe integrity can be maintained even if students' school IDs are allowed, and that the tougher voting laws are more harmful than helpful.

"This represents the people in our country who continue to cling to ... doing things from the past," Lawson said. "They're not ready to move in a fresh human way in the 21st century."