During a Wednesday rally at the University of Iowa in Iowa City, a protester hurled tomatoes at Donald Trump after the Republican presidential frontrunner referred to Bernie Sanders as a  communist. In a news release, officials said Andrew Joseph Alemao, 28, was observed throwing two tomatoes at Trump, the real estate mogul and front-runner for the Republican presidential nomination.Alemao has been charged with disorderly conduct, a simple misdemeanor punishable by a fine of up to $625 or 30 days in prison. He is currently being held in the Johnson County Jail.He was taken into custody by the Secret Service and the UIPD after throwing the tomatoes, the release said.At least three Sanders supporters were apparently escorted by security out of the rally, with Trump shouting,  Get  em outta here!  to the cheers of his fans in the crowd.Not one of the tomatoes actually hit Trump.But it shouldn t matter.Frankly, regardless of how vile, obnoxious and ultimately dangerous Trump might be, there s simply no excuse for anyone to engage in physical violence against him, or any public figures for that matter. It s childish, unacceptable behavior   especially for liberals who ought to know better. If activists are incapable of making an argument using words, evidence and reason, they should figure out how it s done, rather than embarrassing the rest of us (especially other Bernie supporters) by lashing out like an infant who refuses to eat and hurls his food at the wall in protest.The same goes for pie attacks against William Kristol and Ann Coulter, or red paint attacks against Condoleezza Rice. In fact, at the time, I wrote something similar when a protester attacked George W. Bush by throwing shoes at the former president. Feel free to applaud these kinds of attacks   I m sure it s cathartic   but know that by encouraging such atrociously violent, kneejerk behavior, you re only encouraging more of it.And, so, don t be surprised when conservative activists retaliate with the same thing against liberal leaders and celebrities, not unlike how a pissed off wingnut attacked Hillary Clinton back in 2014. Put another way: it s probably not difficult for Trump supporters to worm their way into Democratic rallies.Just to be clear: it s entirely possible that the tomato-tosser wasn t a Bernie supporter at all. Featured image via video screen grab.