The Supreme Court on Monday officially wiped out a lower court ruling from April that had struck down Michigan’s congressional map as giving an unconstitutional boost to Republicans.

The high court’s move was expected, since the justices decided in June that federal courts can’t rein in politicians who draw political maps to entrench a partisan advantage.

If it had stood, Michigan would have had to redraw state legislative and congressional districts ahead of the 2020 elections, and it could have set up a more favorable battlefield for House Democrats.

In April, a panel of three federal judges had invalidated portions of the state and congressional maps drawn by the GOP-controlled Legislature in 2011 as violating the rights of Democratic voters.

[Supreme Court term to be punctuated by presidential politics]

After the 2018 midterms, Michigan’s 14-district House delegation was evenly split between the two parties, 7-7. (Republicans have since dropped to six seats after Justin Amash became an independent in July.)

The League of Women Voters and some Democrats challenged the 1st, 4th, 5th, 7th, 8th, 9th, 10th, 11th and 12th districts, and the three-judge panel found that all nine of them were partisan gerrymanders “because they dilute the views of Democratic voters.”

But the ruling never went into effect. Republican members of Michigan’s congressional delegation and state lawmakers appealed to the Supreme Court, which put the ruling on hold as the justices decided two other cases about partisan gerrymandering in North Carolina and Maryland.

In June, the justices, in a 5-4 opinion, found the Constitution did not give federal courts the authority to strike down maps as partisan gerrymanders. Instead, the majority wrote, that was a political question and a task for Congress and the states.

The dissent in the case contended that lower courts have coalesced around standards for determining when a political map has too much politics, and checking these gerrymanders “is not beyond the courts.”

The Supreme Court’s decision kept the current congressional maps at issue in the cases, and, in addition to dooming the Michigan ruling, also doomed a similar partisan gerrymandering challenge in Ohio, where a federal court also ordered new congressional districts.

The House in February passed a bill that would require independent commissions to oversee redistricting in each state, but Senate Majority Leader Mitch McConnell controls the floor and expressed major concerns about the legislation.

The court action also comes just ahead of the 2020 census and the ensuing redistricting process based on the census results that states use to draw congressional maps — which in turn will affect the partisan makeup of the House and potentially which party is in control of the chamber.