She was offended that Tapper would attempt to "besmirch" Trump supporters like that.
The identity of the man, who wore a "Hillary for Prison" T-shirt, was not immediately clear.
"Wow, I have to push back on some of the adjectives you just used to describe", Conway said, before describing those who attend Trump rallies as "U-S-A. -loving Americans".
Trump's supporters have always been aligned with white supremacy groups and antisemitic sentiment, and this display is further proof of that.
The term "deplorable" has been embraced by Trump supporters after Hillary Clinton said at a fundraiser that half of her rival's supporters were a "basket of deplorables.' She later said she shouldn't have said 'half" and she was referring to the extremes of his support base.
In his defense, Trump and his supporters cite the fact that his daughter, son-in-law and three grandchildren are all Jewish.
Looking like a late 90s surfer movie character gone wrong, a over-confident Trump supporter chose to mock the assembled press at a Trump rally with some anti-Semitic chanting on Saturday.
Conway, appearing on CNN's "State of the Union" with Jake Tapper, was asked whether the Trump campaign denounced such anti-Semitism.
In March, 69-year-old supporter Birgitt Peterson went viral after she was photographed giving the Nazi salute. "These are USA loving Americans who just want their country to be prosperous and safe again".
"I think for the voters at this stage, this plays right into their reluctance about Hillary Clinton", Kellyanne Conway told ABC's George Stephanopoulos on "This Week". "He just has. He says things like, "Oh, sure, I disavow, I disavow.' But he has never serious said, 'I don't want the support of those people, they are reprehensible, they have nothing to do with me.' He has never seriously done it".
"There are what I call the deplorables - the racists, you know, the haters, and the people who are drawn because they think somehow he's going to restore an America that no longer exists". One California nationalist leader is self-funding radio ads for Trump.