A person takes a photo of Kendra Horn as she speaks to supporters during her during her congressional campaign kickoff event in Oklahoma City, Thursday, July 13, 2017. Photo by Bryan Terry, The Oklahoman

Kendra Horn raised more than four times as much money as U.S. Rep. Steve Russell over a recent three-month span, a surprisingly strong showing for the Democratic challenger as she attempts to unseat the Republican incumbent.

Horn raised $442,711 between July 1 and Sept. 30, the last fundraising quarter before the Nov. 6 general election and the quarter most closely watched by political observers. Horn spent $289,245 in the quarter and had $178,276 in her campaign coffers when October began.

"Fewer than fifty Oklahomans supported Steve Russell's campaign in the last three months," Horn said in a statement Tuesday. "Instead he's feasting on corporate PAC money. In turn, he's voted to cut funding for education, to make health care more expensive and to end coverage for pre-existing conditions. He's doing the bidding of corporate PACs and party bosses, not what's right for Oklahomans."

Russell, a two-term incumbent facing the most difficult general election of his congressional career, raised $97,836 last quarter and spent $125,984. His campaign had $446,743 on hand at the start of October.