Democratic 2020 presidential contender Pete Buttigieg argued Sunday that President Trump's tough talk on socialism in the United States is outdated.

"I think he's clinging to a rhetorical strategy that was very powerful when he was coming of age 50 years ago, but it's just a little bit different right now," Buttigieg, 37, said on CNN. "If you grew up during that Cold War period, then you saw a time in politics when the word socialism could be used to end an argument. Today, I think a word like that is the beginning of a debate, not the end of a debate."

Buttigieg, the mayor of South Bend, Ind., who spent the later part of last week in Iowa talking to voters in the early-voting state, said the U.S. is still committed to democracy and its market-based economy.

During his second State of the Union on Tuesday, Trump said he was "alarmed by the new calls to adopt socialism in our country," referring to Democratic talk of a 70 percent marginal tax rate and expanded government-financed healthcare.

Buttigieg announced in January he had established an exploratory committee to look at a potential White House bid. The mayor is among about a dozen high-profile Democrats making official moves toward their party's nomination next year. He is the youngest prospective candidate so far and, if elected, would be the youngest president.