Literally.
Watch the video.
Nearly four months ago, Fetterman suffered a stroke. The video, from a recent and rare campaign stop, suggests that he's not recovering well.
Fetterman was, essentially, foisted on Pennsylvania voters as the Dem candidate for Senate by the Dem smoke filled room. He had no opponent in the primary.
Dr Oz is a weak candidate, politically, but Fetterman is frail physically.
Oz is dabbling in exposing Fetterman's health issues in various ways, playing clips of Fetterman stammering in YouTube ads and taunting him to debate.
Bottom line. Fetterman isn't physically fit enough to serve as a US Senator.
Still, Oz is so pathetic a candidate, Fetterman may win.