The Supreme Court is gearing up next term to wade into two major battles over how Americans vote in elections, with cases over how much of a role race plays in drawing voting districts and who has the final say on election procedures.

Progressive lawyers are bracing for their worst fears to be realized, saying if the justices rule against them in both cases, it would “upend” the Democratic process.

“The two lawsuits could drastically limit the ability to attack suppressive voting laws and protect voters in court,” Marc Elias, who was Hillary Clinton’s campaign lawyer, warned on Twitter.

A case out of Alabama goes to the heart of Section 2 of the Voting Rights Act of 1965, which bars states from making changes to voting laws that purposely discriminate based on race, ethnicity or language.

A federal three-judge panel ruled against Alabama’s attempt to draw lines for its seven congressional districts after the 2020 Census, saying a state where Black residents make up 27% of the population should have two majority-Black districts.

State officials, who have appealed the panel’s ruling to the justices, say they took a race-neutral approach to drawing their maps, barely changing them from the previous set, and leaving Alabama with one majority-Black district.

The state says that if it is forced to create a second Black-dominated district that would effectively be elevating race above all other considerations in the map making.

The Supreme Court in a 5-4 ruling earlier this year stayed the lower court decision, meaning November’s elections will take place under the state’s preferred map.

The justices’ willingness to take up a Voting Rights Act case is worrying to liberal activists.

They are still reeling from a 2013 ruling when the justices, in a 5-4 decision, said the law’s Section 5 process — which gave the Justice Department a veto over election changes in some states with a history of racism — was outdated.

Eugene D. Mazo, a law professor at Seton Hall University, said the justices now appear ready to limit the ways the anti-discrimination provisions in Section 2 can be wielded against states.

“The Supreme Court has tried to cabin the effect of the Voting Rights Act,” Mr. Mazo said. “My view is they are going to try to cut back on Section 2.”