As a state senator in 2014, Ward convened a nearly two-hour hearing on the conspiracy theory that the government is poisoning the populace by spraying chemicals, known as "chemtrails," from airplanes. Ward maintains she was simply responding to the concerns of her constituents and hoped that actual experts might be able to dispel their concerns, although she said at the time that she was "open" to introducing legislation on chemtrails.

The pro-McCain group Arizona Grassroots Action has run an ad mocking Ward's hearing, featuring text composed in skywriting script. McCain's campaign has dubbed Ward "Chemtrail Kelli" and last week released an ad with footage of Ward's chemtrails hearing, charging that the state senator "fuels conspiracy theories at taxpayer expense."

But the chemtrails hearing was hardly a one-time incident. In her short political career, Ward has flirted with the conspiracy-theory fringe by making appearances on 9/11 truther radio programs, advising citizens to stay vigilant against UN helicopters, warning against government "indoctrination," and proposing an unusual theory that the Affordable Care Act was part of a plot to force rural residents to move to cities.