Don't believe us? We have the picture to prove it.
In the picture, Rubio appears to be undertaking one of the less exciting campaign jobs: making signs for an event. (Sorry if we dashed your dreams by revealing that such signs are not always the spontaneous product of enthusiastic supporters.) "Stop lying to America," the sign he's working on reads, with another beneath it, reading something like "tell the truth."
What, exactly, Clinton was being asked to tell the truth about is lost to history. But part of the beauty of the sign is its universality. One can easily picture protesters rolling up to a Hillary Clinton event, waving the same sign with the same weird, dotted "i."
Not to mention the sign draped over the ... upside-down garbage can (?) in the background. "Clinton AWOL on ..." something, it reads. For an ambitious Rubio supporter in 2016, feel free to fill in the blank.