The Democratic nominee in a Pennsylvania special election for a U.S. House seat called for a tax increase on the middle class in a video posted online.

Marc Friedenberg, a college professor who lost the election for Pennsylvania's 12th Congressional District last November, is now hoping to be elected after Republican Representative Tom Marino resigned in January. Marino beat Friedenberg by 32 points in a district that went heavily for President Trump in 2016.

"We should be raising taxes on the middle class so that they're paying their fair share," he said in an online video that was posted on his Facebook account in December of 2017.

In numerous instances during the video that runs just under three-and-a-half minutes, Friedenberg appears to read off a script.

"This is an outrageously unfair hit piece that blatantly takes a slip of the tongue in an old video out-of-context to hide the fact that our opponent supports destroying Social Security," said Gregory Minchak with the Friedenberg campaign. "The entire video discusses that to pay for massive tax cuts for billionaires and international conglomerates, Republicans like Fred Keller want to end Social Security as we know it. Unlike his opponent, Marc has consistently called for middle class tax cuts, affordable health insurance, and the saving of Social Security."

Many Democratic congressional candidates in 2018 ran on a narrative of trying to reframe the Republican tax cuts as a tax increase on the middle class.

The race is drawing extra attention now that California billionaire Tom Steyer, best known for his efforts to impeach the president, has announced he and his political action committee NextGen America will be dedicating resources to the special election that concludes in one month.

The Friedenberg campaign has welcomed the support, which is mainly believed to be in the form of voter registration and get-out-the-vote efforts.

"While we have zero engagement with NextGen, we believe it demonstrates how important this race is to the state," Minchak said to PoliticsPA.com. "This race will decide if Pennsylvania is to be a leader in alternative energy development, creating new infrastructure that will support good paying jobs, and stopping the brain drain plaguing the district. According to the media report, NextGen is focused on getting students politically engaged, which should be welcomed by both candidates."

If Democrats have welcomed the news of Steyer's involvement, so have Republicans.

"Tom Steyer has found new ways to light his money on fire, this time by backing socialist Marc Friedenberg in a district President Trump won by 36 points," said Michael McAdams, press secretary for the National Republican Congressional Committee. "Given the last thing PA-12 voters want is a California billionaire telling them how to vote, this is essentially an in-kind donation to Republicans."

Of the small number of Facebook ads Friedenberg's campaign is currently running, two support "Medicare for All." The candidate has also spoken in general terms in support of the "Green New Deal," but it is unclear if those comments represent a full-on endorsement of the controversial proposal by the most liberal wing of the new Democratic House majority.

The district is located in north central and north east Pennsylvania. Marino resigned to take a job in the private sector and to focus on health issues.

Friedenberg will face off against Republican Fred Keller on May 21.