Henderson, who served two tours of duty with the Army in Iraq and one in Afghanistan, had the backing of Congressman and Philadelphia Democratic chairman Bob Brady.
He easily won the Philadelphia portion of the district, but lost in Montgomery County. The final vote total, according to the Associated Press, was 3,758 votes to 3,191.
WHYY NewsWorks reports that Henderson has not conceded.
DeLissio stumbled in the early going of the campaign when it was revealed that she was legally a resident of Dauphin County. She narrowly survived a ballot challenge earlier this spring.
Editor’s note: Based on the Philadelphia returns, PoliticsPA mistakenly said Tuesday night that Henderson had won.