The US state of Louisiana will hold several primary elections on Thursday, including for the United States Senate, the state’s Supreme Court, and a slate of local offices.

Notably absent will be the primary, in which members of the Democratic and Republican parties will select their candidates for the state’s six US House districts ahead of the general elections in November.

The primary vote has been paused by the state’s governor following a major Supreme Court ruling that opens the door to redrawing the state’s congressional district map, eliminating one of two majority-Black districts.

Rights groups have challenged the pause, saying it violates both the US and the state’s constitutions.

The situation comes amid a wider national redistricting battle, which has been shifting both parties’ electoral calculus ahead of consequential midterms that will determine control of the US House and Senate and, in turn, set the tone for the final two years of US President Donald Trump’s second term.

Here’s what to know.

What did the Supreme Court ruling do?

The 6-3 Supreme Court ruling in late April undid a key provision of the Voting Rights Act of 1965 meant to protect Black voting power from being diluted.

That can be achieved by effectively carving up areas with large Black populations to diminish their electoral influence. Black voters in the US have historically heavily skewed Democratic.

The ruling said that congressional districts could only be challenged if there was evidence of racist motivation behind how they were drawn. Dissenting liberal justices and critics have said such motivations would be exceedingly difficult, if not impossible, to prove.

Specifically related to Louisiana, the court ruled that a congressional map drawn in January of 2024, which created a second Black-majority district in the state, was unconstitutional.

That map was created following a legal challenge claiming that Louisiana was in violation of the Voting Rights Act because it had only one Black majority district out of six, despite Black residents making up one-third of the state’s voters.

Why did Louisiana pause its primary?

The Supreme Court ruling on April 29 came about two weeks before Louisiana’s US House primary elections were scheduled.

That left Republicans in the state scrambling to draw new maps ahead of the vote.

“Allowing elections to proceed under an unconstitutional map would undermine the integrity of our system and violate the rights of our voters,” the state’s Governor Jeff Landry said in a statement on April 30.

He said his order suspending the vote “ensures we uphold the rule of law while giving the [state] legislature the time it needs to pass a fair and lawful congressional map”.

On Wednesday, Republicans in the Louisiana State Senate advanced an initial redrawn map.

What have rights groups said?

A coalition of voting and civil rights groups has challenged the suspension of the election, charging that some segments of voters, including those in the military or casting “absentee” ballots, may have already voted.

They further said the abrupt change in date would confuse and subsequently disenfranchise voters while undermining voter education groups already distributing information about the election.

“This illegal executive order threatens the integrity of our democratic system and disregards the voices of voters who have already participated in the May primary election in good faith,” the groups, which included the Legal Defense Fund, the League of Women Voters of Louisiana, the American Civil Liberties Union, and the Harvard Law School Race and Law Clinic, said in a joint statement in early May.

“By attempting to suspend an ongoing election, state officials are creating confusion, undermining public trust, and placing partisan interests above the constitutional rights of Louisiana voters,” the statement said.

What is the wider context?

The standoff in the southern state comes amid a wider, and unorthodox, flurry of congressional redistricting in the US.

While redistricting has historically taken place every decade following the US census population count, President Trump called on Republicans in Texas last year to redraw their maps to create more Republican-leaning districts.

That kicked off a flurry of tit-for-tat redistricting efforts by Democratic- and Republican-controlled state legislatures alike. To date, the US states of California, Missouri, Ohio, Virginia, Utah, Tennessee and Florida have redrawn their maps ahead of the midterms.

Republicans are expected to net more seats than Democrats in the push. While that is expected to cut into the margin, Democrats are still tentatively favoured to retake the US House in November.