HARRISBURG — Democrats celebrated a clean sweep of three open seats on the Pennsylvania Supreme Court as the party locked in a majority on the state’s highest court for at least a decade that could help shape the legislative redistricting that will follow the 2020 census.

The winners of the seven-way race were Philadelphia Judge Kevin Dougherty and Superior Court judges David Wecht and Christine Donohue of Allegheny County.

The Democratic takeover was fueled by cash provided largely by organized labor and Philadelphia trial lawyers to help sustain TV advertising. Of the record $11.5 million contributed to the seven candidates, Democrats raised three times as much as the Republicans.

It was the first time so many seats on the high court were open in an election.

Wecht said he felt his focus on ethical issues made the difference in the campaign. He said he hoped the high court has put its own trials and tribulations behind it.

“The people of Pennsylvania are entitled to justices who are actually focused on law, and not on other stuff,” he said.

Donohue said she was impressed by the unity of the Democrats and “tickled” to be elected to the court.

“It’s such a humbling experience,” she said.

When the new justices take their oaths in January, they will round out a 5-2 Democratic majority.

Justice Debra Todd, a Democrat now on the Supreme Court, is all but guaranteed a second 10-year term in 2017, when she’ll stand unopposed in a yes-or-no vote on whether to retain her through 2027.

Republicans have controlled the court for six years and currently have a 3-2 advantage that includes an interim justice who will be displaced by one of the Democrats.

The losing GOP candidates were Superior Court Judge Judy Olson of Allegheny County, Commonwealth Court Judge Anne Covey of Bucks County and Adams County Judge Mike George. Paul Panepinto, a Republican-turned-independent, finished in last place.

Democrats also won two other appellate court races.

Philadelphia Judge Alice Beck Dubow claimed a seat on the Superior Court. Pittsburgh lawyer Michael Wojcik won a spot on the Commonwealth Court.

On the high court, two seats were open because of the resignations of disgraced former justices: in 2013, a Republican convicted of using her taxpayer-paid staff to do political work and, in 2014, a Democrat implicated in a pornographic e-mails scandal.

The other seat became vacant when former Chief Justice Ronald Castille was forced to step down last year after reaching the mandatory retirement age of 70.

Supreme Court justices are elected to 10-year terms. After that, they face retention votes for additional terms.