"Shame on you Bernie," the man said as he stood up in the third row of the auditorium, feet from the Democratic presidential candidate.
"Here is a Trump supporter," Sanders said from the stage, causing the entire crowd to boo the proud protester as he was being escorted out by Sanders' staff.
The man, who fist-pumped as he exited the room, also held a sign that read, "Obama is as Christian as Bruce Jenner is a woman."
After the protester was escorted out, Sanders said, "I say to Mr. Trump and his supporters that the billionaires of this country will not continue to own this nation."
The incident, which lasted less than a minute, fired up the already excited Sanders supporters, who chanted "Ber-nie, Ber-nie, Ber-nie" to drown out the protester.
Sanders has made a point of knocking Trump at his events while also knocking the media for consistently covering the Republican front-runner.
After Trump falsely asserted last month that Sanders wants to raise taxes to 90%
, the Vermont senator hit back by calling the boisterous businessman a "pathological liar."
"It appears that Donald Trump, a pathological liar, simply cannot control himself. He lies, lies and lies again," Sanders said in a statement. "Today, he repeated his lie that I want to raise taxes to 90 percent. Totally untrue."
Trump has doubted Sanders chances to win the nomination and questioned many of his decisions as a candidate.
"I call him a socialist-slash-communist, because that's what he is," Trump said in October.