Speculation that Clinton has employed a body double to hide illness has spread on right-wing websites in the aftermath of her swift departure from the ceremony last weekend. The Clinton campaign dismissed the idea as an absurd conspiracy theory, but that won’t put an end to the rumor—or others like it—for anyone inclined to believe. “There is something the campaign is hiding,” Ashley, who identified herself as a progressive, told me in an e-mail. “They want to call any question of her health a conspiracy theory. It’s not a theory, it’s a fact.”

Such conspiracy theories are far more likely to originate in—and be spread by—conservative media and far-right corners of the Internet than in the Sanders crowd. High-profile Republicans have engaged in aggressive speculation about Clinton’s health in a way that has no equivalent on the political left. Republican nominee Donald Trump has implied that Clinton is not physically fit to serve as commander in chief. At an Ohio rally Wednesday night, he posed this question to the crowd: “I don’t know folks, do you think Hillary Clinton would be able to stand up here for an hour? I don’t know.” Television personality Sean Hannity has used his platform on Fox News to provide airtime to speculation over Clinton health problems.

Still, the tendency to raise vague questions—as well as make specific claims without concrete evidence—about Clinton’s health clearly exists across the political spectrum. Some disappointed Sanders supporters appear to be promoting full-fledged, unproven narratives about Clinton’s health, while others seem willing to believe a cover-up might exist, even if they don’t go so far as to articulate what Clinton might be covering up.

The possibility of a cover-up even seems to have kept some Sanders supporters’ hopes alive that he could get back in the race. “This does NOT look like heat exhaustion to me,” a Reddit user recently commented in response to video showing Clinton leaving the 9/11 memorial. “It looks like she has a serious neurological disease; maybe she was having a stroke, maybe she has MS. Whatever it is, we the people need to know. SOON! Bernie must replace her, NOT Tim Kaine or Joe Biden!”

At a rally against the Dakota Access pipeline on Tuesday in Washington, D.C., Oscar Salazar, a self-described Democrat, told me that he wants Clinton “to be as healthy as possible.” He was quick to add, though, that “if she’s not able to come out and rally everyone to come together and vote against Donald Trump, then Bernie should take over.” Salazar, who was sporting a onesie with Sanders’s face printed all over it, said that after seeing video of Clinton leaving the ceremony, he “think[s] there’s something going on, and she’s not really coming out and saying what it is, which is making her look bad even more.”