PHILADELPHIA — Mehmet Oz sees an opening to rescue his floundering Senate campaign: After largely refraining from making his opponent’s health an issue, the celebrity doctor has decided to go there.

Oz’s Democratic opponent, John Fetterman, suffered a stroke in May and since then, has largely avoided public events and been noncommittal about debates. Instead, he’s been relentlessly trolling Oz on social media and dominating the airwaves with campaign ads. Meanwhile, Oz has struggled to consolidate support from the conservative base, despite former President Donald Trump’s endorsement.

Until now, Oz — a TV physician popularly known as Dr. Oz — hasn’t directly made Fetterman’s health challenges an issue in the race. But in the last week, Oz has changed tactics.

This week, his campaign put out two statements ridiculing Fetterman’s diet and accusing him of being too ill to withstand debates. Oz and his campaign have also been working behind the scenes to convince prominent conservative figures — including those who were once detractors — to publicly rally around him. Republicans hope that delayed support from influential conservative commentators will help him persuade unenthused rank-and-file GOP voters to come home to him.

“He has turned the corner,” said John Fredericks, a conservative radio host and Trump ally who encouraged the former president to endorse Oz in the primary. “One of the key reasons he’s done that is he has been able to now meld together the entire MAGA movement, which is coming behind him because they don’t want Fetterman.”

Mehmet Oz, a Republican candidate for U.S. Senate in Pennsylvania, takes part in a Republican Jewish Coalition event in Philadelphia, Aug. 17, 2022.