Sen. Elizabeth Warren was forced to defend her wealth despite her frequent attacks on the rich after she was confronted by a Boston radio host earlier this week.

Ms. Warren, a Massachusetts Democrat who frequently attacks big banks and Wall Street, ran into WRKO radio host Jeff Kuhner at the studio Monday and was asked how she can justify “railing” against a class of Americans to which she belongs.

“Question: You often say, and I agree with you, that the 99 percent are getting shafted by the one percent. You live in Cambridge, you’ve got a $2 million mansion,” Mr. Kuhner said as Ms. Warren nodded in agreement. “Plus you’re a multimillionaire yourself. How can you rail against the one percent, when in a sense, you are and live like the one percent?

Ms. Warren launched into her biography about her modest childhood and not having enough money to apply to college, much less being able to afford to attend. She started to get visibly annoyed when Mr. Kuhner interjected, saying, “You made millions of dollars, right? And you live in a mansion in Cambridge.”

Ms. Warren said she got to where she is today because she was able to attend a state law school that only charged $450 a semester.

“That’s how I had opportunity and I am deeply grateful to an America that made those opportunities possible. Those opportunities are not available in America today,” she said, speaking over Mr. Kuhner. “I had opportunities because America invested in kids like me, and that’s the reason I’m in public office.”

"I know,” Mr. Kuhner responded. “But you’re part of the one percent and you rail against the one percent. You don’t see the hypocrisy there?”

“It’s not hypocrisy!” the senator exclaimed. “What this is about is whether you believe in opportunity or not.

“I believe in opportunity and it’s what I fight for,” she said as she walked away.

According to a 2015 report by CNN, Ms. Warren is worth between $3.7 million and $10 million, not including her three-story home in Cambridge.

In a blog post Wednesday, Mr. Kuhner, a conservative and former columnist at The Washington Times, called Ms. Warren “a liar and a hypocrite” who was visibly embarrassed by his questions.

“Warren champions economic collectivism and state socialism. Her philosophy can be distilled to one seminal idea: Capitalism is evil,” he wrote. “She is a typical socialist. She preaches class hatred and the demonization of the rich, but lives — like the ruling Communists in Soviet Russia, Cuba or Venezuela — in opulent splendor. … She is a crony capitalist masquerading as a principled progressive.”