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Pennsylvania Senate candidate John Fetterman's campaign is alleging that the closed captioning system used to assist the Democrat in Tuesday's debate against Republican Dr. Mehmet Oz was slow and full of errors, a claim the debate host refutes.

Fetterman is recovering from a stroke he suffered in May and has since struggled with auditory processing issues and speaking clearly ever since. The campaigns for Fetterman and Oz both agreed that the lieutenant governor could use closed captioning for the debate.

Following the debate hosted by Nexstar, Fetterman communications director Joe Calvello told reporters his boss thrived in his performance on Tuesday despite errors with closed captioning.

"We are thrilled with John’s performance," Calvello said. "He did remarkably well tonight – especially when you consider that he’s still recovering from a stroke and was working off of delayed captions filled with errors. John won countless exchanges, counter-punched aggressively, and pushed back on Oz’s cruelty and attacks."

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John Fetterman

Pennsylvania Senate candidate John Fetterman's campaign is alleging that the closed captioning system used to assist the Democrat in Tuesday's debate against Republican Dr. Mehmet Oz was slow and full of errors. (NewsNation)

However, Nexstar rebuked the allegations from the Fetterman campaign, saying in a statement the Democrat did not utilize all the opportunities he was given to practice before Tuesday night. Nexstar said it offered both candidates two rehearsals but that Fetterman elected to only do one.

"It is unfortunate that Mr. Fetterman is now criticizing the closed captioning process employed by Nexstar during tonight’s debate," Nexstar communications chief Gary Weitman said in a statement. "Both candidates agreed to the technical set-up for the closed captioning process weeks ago, which was implemented at the request of the Fetterman campaign. Both candidates were offered the opportunity for two full rehearsals with the same equipment used in tonight’s debate; Mr. Fetterman chose to do only one."

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John Fetterman, Mehmet Oz

Pennsylvania Senate candidates John Fetterman and Dr. Mehmet Oz participate in a debate on October 25 in Harrisburg, Pennsylvania. (NewsNation)

Weitman explained that Nexstar had ensured the closed captioning process was effective and that the system functioned properly during the debate.

"In fact, Nexstar’s production team went to extraordinary lengths to ensure the effectiveness of the closed captioning process, and to accommodate several last-minute requests of the Fetterman campaign," he said. "The closed captioning process functioned as expected during rehearsal and again during tonight’s debate. We regret that Mr. Fetterman and his campaign feel otherwise."

John Fetterman, Dr. Mehmet Oz during a debate

John Fetterman is recovering from a stroke he suffered in May and has since struggled with auditory processing issues and speaking clearly ever since. The campaigns for Fetterman and Dr. Mehmet Oz both agreed that the lieutenant governor could use closed captioning for the debate. (NewsNation)

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Human captioning transcribed every word spoken by the moderators and Oz, but Fetterman's remarks were left out, according to WHTM. The captions were shown on two 70-inch monitors displayed behind the moderators.

According to a FOX News poll conducted last month, Fetterman leads Oz 45% to 41% among likely Pennsylvania voters.

Fetterman’s campaign did not immediately respond to FOX News Digital's request for comment.