A recent decision by the Supreme Court rejected a congressional district map in Missouri that favored Republicans. The ruling, issued without explanation, means the state will likely use a previous map that included six seats the Republicans could win, rather than seven.

This decision is seen as an unusual defeat for Republicans in an election matter before the conservative-leaning Supreme Court. The impact is expected to be limited to one seat.

Further information on this development is available from the source, including details on the potential effects of the ruling on upcoming elections.