Story highlights Clinton unleashes her harshest attack on the GOP frontrunner

The leading Democrat's response comes after Trump used a vulgar term

Des Moines, Iowa (CNN) Hillary Clinton said Donald Trump's recent vulgar description of her electoral loss in 2008 was "not the first time he's demonstrated a penchant for sexism."

Clinton said the GOP frontrunner thrives on controversy in her first direct response to Trump telling an audience that she got "schlonged" -- a term derived from a vulgar Yiddish word for a man's penis -- when she lost to then-Sen. Barack Obama in the 2008 fight for the Democratic presidential nomination.

"I really deplore the tone of his campaign, the inflammatory rhetoric that he is using to divide people, and his going after groups of people with hateful, incendiary rhetoric," Clinton said in an interview with the Des Moines Register's Tony Leys on Tuesday in Fairfield, Iowa.

"Nothing really surprises me anymore. I don't know that he has any boundaries at all. His bigotry, his bluster, his bullying have become his campaign. And he has to keep sort of upping the stakes and going even further."

She added, "I don't respond to him personally, because he thrives on that kind of exchange. I think he has to answer for what he says, and I assume that others will make the larger point about his language. It's not the first time he's demonstrated a penchant for sexism. Again, I'm not sure anybody's surprised that he keeps pushing the envelope."

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