click to enlarge File: Paul Heintz

Former governor Howard Dean at the Democratic National Convention in Philadelphia

Notice Trump sniffing all the time. Coke user? — Howard Dean (@GovHowardDean) September 27, 2016

As Republican presidential nominee Donald Trump sniffled away Monday night during the first debate of the general election, former Vermont governor Howard Dean posited a theory as to what was causing all the nasal activity."Notice Trump sniffing all the time," he wrote on Twitter. "Coke user?"Rather than apologize for the off-color tweet the next day, the former practicing physician doubled down on it Tuesday afternoon in an appearance on MSNBC "Well, you can't make a diagnosis over the television," he said. "I would never do that. But he has some interesting — that is actually a signature of people who use cocaine. I'm not suggesting that Trump, but—""Well yousuggesting it, actually, in a tweet," MSNBC host Kate Snow interjected."No, I'm suggesting weabout it," Dean said. Then he rattled off a list of symptoms he said Trump shared with cocaine users, ranging from "grandiosity" to "delusions" to "trouble with pressured speech." "Do I think at 70 years old he has a cocaine habit?" the ex-gov continued. "Probably not. But, you know, it's something that I think would be interesting to ask him and see if he ever had a problem with that."For several more excruciating minutes, Dean claimed he wasn't accusing Trump of using drugs while repeating the suggestion that he might be — employing similar rhetorical tactics as when Trump and his surrogates accused Democratic nominee Hillary Clinton of hiding a grave illness and President Barack Obama of being foreign born."I don't think this was a ridiculous idea," Dean said. "Something funny was going on with Trump last night. Do I think it was cocaine? Probably not. But, again, the sniffing, the grandiosity, the delusions, the pressured speech. You know, this guy has already proven himself unstable. The question is: Why is he unstable?"