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]