BALTIMORE — Donald Trump criticized Hillary Clinton for her characterization that half of his supporters belonged in “a basket of deplorables,” denouncing the comment as “an explicit attack on the American voter” and suggesting that it makes her unfit for the presidency.

No stranger to making his own sweeping negative characterizations of large groups of people, Trump nonetheless deployed the remark Monday as the foundation for a new campaign theme. The message: Clinton is divisive, while Trump is the only candidate representing “all Americans.”

“You cannot run for president if you have such contempt in your heart for the American voter,” Trump said. “You can’t lead this nation if you have such a low opinion of its citizens.”

In a speech to the National Guard Association conference in Baltimore, Trump said Clinton’s comments were aimed at those in uniform.

“These were the people Hillary Clinton so viciously demonized,” said Trump, who demanded that Clinton issue a full apology. “She divides people into baskets as though they were objects not human beings.”

Clinton has said she regrets using the term, “half,” to describe the proportion of Trump supporters she considers “deplorables.” But she didn’t back down from describing his campaign as largely built on prejudice and paranoia.