Pennsylvania state Rep. Fred Keller R) speaks as President Trump looks on during a campaign rally in Montoursville Pa., on May 20, 2019. (Matt Rourke/AP)

Republican state Rep. Fred Keller easily beat Penn State professor Marc Friedenberg (D) in a special election Tuesday in Pennsylvania’s heavily Republican 12th Congressional District.

The seat was vacated in January by Rep. Tom Marino (R), who left for a job in the private sector. With 53 percent of precincts reporting, Keller had 70 percent of the vote compared with nearly 30 percent for Friedenberg.

Friedenberg was also the Democratic nominee in 2018, when he lost to Marino by 32 percentage points.

Pennsylvania redrew its congressional districts in 2018. The current 12th District, which covers a large and deeply conservative swath of the north and central parts of the state, voted 66.1 percent for Donald Trump in the 2016 presidential election.

Shortly after beginning his fifth term in Congress, Marino announced in January that he was resigning later that month to take a private-sector job.

Trump nominated Marino to be the nation’s drug czar in 2017. But Marino withdrew from consideration after a Washington Post/“60 Minutes” investigation detailed his role as the chief architect of a law that undermined government efforts to crack down on the opioid industry.

Trump tweeted his support of Keller on Monday and made a campaign stop in the district to support him. At a rally in Montoursville, Trump called Keller a “tough man” who is “tough on crime.”

“He loves our military. He loves our police. He loves our vets. And he will always protect patients. . . . We will always protect preexisting conditions,” said Trump, despite his administration’s efforts to gut the Affordable Care Act.

Health care looms as a major issue in 2020, with the Trump administration pushing the courts to declare the entire ACA unconstitutional. The 2010 law ensures that insurance companies cannot deny coverage to Americans with preexisting medical conditions. Republicans have failed to craft a health-care plan that provides the same protections.

Keller, wearing a bright red tie and dark jacket, bore an uncanny resemblance to Trump as he stood next to the president onstage.

“The people of northeastern and north-central Pennsylvania have been behind you since Day One,” he told Trump. “And Mr. President, our support for you is as strong today as it ever was. In 2016, Pennsylvania put Donald Trump over the top. And in 2020, we’re going to do it again!”

Friedenberg responded to the rally in a tweet Monday night.

“If tonight tells you one thing, let it be this. Our campaign is fueled by every day, working people, while our opponent @VoteFredKeller has vowed to be nothing more than a puppet for corporate interests,” the Democrat said.

Friedenberg had repeatedly sought to tie Keller to Trump’s trade policies, which the Democrat argued are hurting Pennsylvania’s agricultural and manufacturing industries.

After Tuesday’s election, two vacancies will remain in the 116th Congress. One is in North Carolina’s scandal-plagued 9th Congressional District; the other is for the seat of the late representative Walter B. Jones (R-N.C.). Both vacancies will be filled by special elections in September.

Mike DeBonis and Anne Gearan contributed to this report.