The US is on the brink of the largest reduction in Black representation in Congress since the enactment of the Voting Rights Act almost 61 years ago.

House Democrats could lose six Black members after this year’s midterms due to a redistricting campaign that intensified after the Supreme Court gutted the power to bring claims of racial discrimination under the voting law. Two of the incumbents in redrawn districts will not return to office next year and the remaining four are underdogs to keep their seats.

A seventh Black lawmaker, Republican Rep. Burgess Owens of Utah, is leaving the House after a judge struck down a map that had favored the GOP.

Winning this fall’s midterm elections, not maintaining racial representation, was the stated target of Republicans who launched an unprecedented mid-decade sweep of redrawing US House maps across the country and Democrats who responded with their own push. But the results of that campaign – and the US Supreme Court’s ruling – could lead to a historic erosion of Black political power, particularly in the South, where most Black people live.

“What the Supreme Court has done is sanction discrimination against African Americans in the political process,” Derrick Johnson, the president of the NAACP, told CNN. “The only time in history that we’ve seen this is after Reconstruction.”

Black Americans spent the first century after the country’s founding without the right to vote and much of the next century fighting to make it a reality.

A number of Black lawmakers were elected to Congress after the Civil War, when former Confederate states began allowing Black Americans to vote as a condition of rejoining the Union. Federal troops stationed in the South helped ensure Black access to the ballot.

But official suppression of the Black vote began almost immediately as troops were withdrawn, sometimes through state-sanctioned violence and murder. By 1877, the Reconstruction era was over, and the end of Black representation in Congress followed.

In all, 20 Black representatives and two Black senators served in Congress between 1870 and 1901.

The 1965 Voting Rights Act was enacted the same year that baton-wielding Alabama state troopers bloodied peaceful voting rights protesters, including John Lewis, on Selma’s Edmund Pettus Bridge.