Thousands of activists are marching in Washington D.C. Saturday for a pair of rallies to demand federal voting rights protections and a wide range of civil rights reforms.

The marches coincide with the 58th anniversary of the Rev. Martin Luther King Jr.’s historic "I Have a Dream" speech at the National Mall. Organizers are pressing for the Democratic-led Congress and White House to enact bold, sweeping election reforms they say are needed in the face of new voting laws in states like Texas and Florida

TEXAS GOP ADVANCES VOTING BILL AFTER DEMOCRATS END WEEKS-LONG WALKOUT

The Rev. Al Sharpton, right, with Martin Luther King, III, left, walk during a march for voting rights, marking the 58th anniversary of the March on Washington, Saturday, Aug. 28, 2021, in Washington. (Associated Press)

The Rev. Al Sharpton, right, with Martin Luther King, III, left, walk during a march for voting rights, marking the 58th anniversary of the March on Washington, Saturday, Aug. 28, 2021, in Washington. (Associated Press)

"We are marching to protect our power, to protect our voice, to protect our voting rights!," tweeted Martin Luther King III, the son of the late civil rights leader.

The "March On for Washington and Voting Rights" on the National Mall is organized by King's group, the Drum Major Institute, the Rev. Al Sharpton's National Action Network, the Service Employees International Union (SEIU) and other voting rights organizations. 

They are calling for the passage of Democrats' sweeping election reform plans – the For the People Act, the John Lewis Voting Rights Advancement Act and making Washington D.C. the 51st state. All three of those initiatives passed the House this year, but face an uphill climb in the Senate where 60 votes are needed to overcome the filibuster and Democrats control just 50 seats. 

Voting rights activist Regina Cosio of Syracuse, New York, dresses as "Ms. Liberty" as she participates in a pre-march rally during a March On For Voting Rights event at McPherson Square Aug. 28, 2021 in Washington, DC. (Getty Images)

Voting rights activist Regina Cosio of Syracuse, New York, dresses as "Ms. Liberty" as she participates in a pre-march rally during a March On For Voting Rights event at McPherson Square Aug. 28, 2021 in Washington, DC. (Getty Images)

Sharpton called out President Biden in a fiery headline speech at the march where he demanded a carve-out to the filibuster to pass voting rights. 

"You said the night you won that Black America had your back and that you were going to have Black America’s back," Sharpton said Saturday. "Well, Mr. President, they're stabbing us in the back. In 49 states, they’ve got their knives out stabbing us in the back."

Sharpton also made a special appeal to moderate Sen. Joe Manchin, D-W.Va., who has opposed both the "For the People Act" legislation and getting rid of the filibuster. He said it was time for Biden to pressure Manchin. 

"You need to pick up the phone and call Manchin and others and tell them if they can carve around the filibuster to confirm Supreme Court judges for President Trump, they can carve around the filibuster to bring voting rights for President Biden," Sharpton said. 

Senate Republicans in 2017 changed the rules under Trump to allow for Supreme Court justices to win confirmation by just a simple majority vote. 

With the Capitol in the backdrop, Sharpton declared: "We’re going to stay on you until you get your carving knife out again."

HOUSE DEMOCRATS PASS JOHN LEWIS VOTING RIGHTS ACT

At the second rally at the Lincoln Memorial, organizers for the "Make Good Trouble Rally" were demanding much more than voting reforms, D.C. statehood and changing the Senate filibuster. Their calls for action also include progressive priorities of passing slavery reparations, raising the minimum wage to $15, canceling student debt, ending gun violence, legalizing undocumented immigrants and reversing climate change. 

Voting rights activists participate in a pre-march rally during a March On For Voting Rights event at McPherson Square Aug. 28, 2021 in Washington, DC. (Getty Images)

Voting rights activists participate in a pre-march rally during a March On For Voting Rights event at McPherson Square Aug. 28, 2021 in Washington, DC. (Getty Images)

Chants in the crowd include "Black Lives Matter" and "Trans Lives Matter." 

Both rallies had a steady lineup of speakers throughout the day, including members of congress, family members of the Rev. Martin Luther King Jr., the late Rep. John Lewis, D-Ga., and of George Floyd, who was killed by former Minneapolis Police Officer Derek Chauvin in May 2020.  

Floyd's death sparked nationwide Black Lives Matter protests that summer and demands for racial justice, policing accountability and defunding the police.

Fox News' Liz Friden contributed to this report.