By MARC LEVY
Associated Press

HARRISBURG, Pa. (AP) - The Pennsylvania Supreme Court is on the cusp of imposing a new congressional district map for the state's 2018 elections, all but ensuring that Democratic prospects will improve for several seats.

The court set a Monday deadline for itself to unveil a map of districts to take effect in the May 15 primary, although Republican lawmakers have said they'll ask federal judges to block any new map. They contend that the court is unconstitutionally commandeering legislative authority to draw districts.

The state's Democratic-majority high court ruled last month in a party-line decision that Pennsylvania's district boundaries were unconstitutionally gerrymandered. Republicans have won 13 of Pennsylvania's 18 seats in three elections under the invalidated map, although Democrats hold a statewide registration edge and most statewide offices.

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