Republicans hold all four seats in the state's House of Representatives in Washington and had presented a map that would have helped protect those districts.
But the proposal “unduly favors Republicans and disadvantages Democrats,” according to Judge Dianna Gibson.
She had previously urged the state's House of Representatives to present a fair proposal and had warned that otherwise she might approve proposals from other claimants in the legal process that led to the redrawing of the current districts.
The winning proposal, put forward by two women's groups, would place almost all of Salt Lake County in one electoral district, a county with a majority of Democratic voters but previously divided among all four Utah districts.
This gives the Democrats a significantly greater opportunity to take a seat in the state from the Republicans in the midterm elections.
