Thousands of protesters kicked off marches in Washington and other U.S. cities on Saturday to demand protections for voting rights, aiming to pressure lawmakers to pass legislation to counter a wave of ballot measures in Republican-led states.

Held on the anniversary of Martin Luther King Jr.’s historic 1963 March on Washington, organizers of the “March On For Washington And Voting Rights” say the state-level moves to curb voting access disproportionately impact people of color.

In Washington protesters holding “Black Lives Matter” flags and signs calling for federal legislation marched from McPherson Square towards the final meeting point at the National Mall, where King gave his iconic “I Have a Dream” speech 58 years ago.

Carolyn Ruff, a 74-year-old activist, said she made the trip from Chicago to Washington to push for the passage of a federal law that would restore key protections of the Voting Rights Act of 1965, which outlawed discriminatory voting practices.

The bill, named after the late civil rights hero John Lewis, was approved in the U.S. House of Representatives this week but faces poor prospects in the Senate due to rules that allow a minority to block legislation.

“I truly hope that if they don’t vote for it in my time, I hope they vote for it in the next generation,” said Ruff, a founder of Black Lives Matter Women of Faith, a group that advocates for social justice.

“I’m asking all of our people: red, yellow, white, brown – we all have to come together. This is why I’m here.”

After Democrat Joe Biden won the 2020 presidential election, Republican lawmakers in many states reined in use of dropboxes and mail-in voting. The moves came after former Republican president Donald Trump tried unsuccessfully to overturn the election based on unsubstantiated claims of widespread voter fraud.

So far this year, at least 18 states have enacted laws restricting voter access, according to the Brennan Center for Justice at New York University.

Organizers expect some 50,000 demonstrators in Washington, where civil rights leaders including Martin Luther King III and the Rev. Al Sharpton are scheduled to speak. Rallies have also been planned in Phoenix, Miami and several other cities.

In addition to the John Lewis Voting Rights Advancement Act, a more expansive voting reform bill was also passed by the House earlier this year but Senate Republicans blocked it in June, saying voting rules should be left to the states.

The lack of meaningful Republican support appears set to doom any legislation in the Senate, which is divided 50-50 along party lines and where filibuster rules mean Democrats need to secure the votes of 10 Republicans to advance measures.

Kathleen Kennedy, 27, said she joined the Washington march after reading about a law in Texas that had garnered national attention after Democratic lawmakers fled the state in an effort to deny a quorum needed for Republicans to pass it.

The bill, which would outlaw drive-through and 24-hour voting locations and add new identification requirements to mail-in voting, among other restrictions, was approved by the state’s House of Representatives on Friday.

“So many of these laws are getting passed. Elections are coming up, elections will be impacted by these laws,” said Kennedy, a resident of nearby Silver Spring, Maryland. “It’s worth ending the filibuster.”