Trump and Willie Horton

Donald J. Trump accused Hillary Clinton on Friday of wanting to let violent criminals out of prison and “disarm” law-abiding citizens in unsafe neighborhoods, and warned that women, in particular, would be at greater risk if she were elected president.

Accepting the endorsement of the National Rifle Association at its annual convention here, Mr. Trump — who has not always been the staunchest opponent of stricter gun controls — said the November election would be a referendum on the Second Amendment. He claimed, hyperbolically, that Mrs. Clinton, his likely Democratic opponent, “wants to take away your guns.”

“Crooked Hillary Clinton is the most anti-gun, anti-Second Amendment candidate ever to run for office,” he said.

Mrs. Clinton has called for tightened restrictions on guns, but not for abolishing the right to own them.

Mr. Trump, whose record of sexist remarks, among other things, has left him at a potentially crippling disadvantage among female voters, polls show, appealed directly to women in his speech, imbuing his defense of gun rights with an undercurrent of fear.

“In trying to overturn the Second Amendment, Hillary Clinton is telling everyone — and every woman living in a dangerous community — that she doesn’t have the right to defend herself,” Mr. Trump said. “So you have a woman living in a community, a rough community, a bad community — sorry, you can’t defend yourself.”

If Mr. Trump’s comments seemed reminiscent of an era when crime rates were far higher — the Willie Horton ads attacking Michael S. Dukakis, the Democratic nominee, in the 1988 presidential race came to mind — they also appeared somewhat at odds with the broad bipartisan consensus on the need to reduce incarceration rates and prison populations: Mr. Trump sought to frighten voters about the idea of criminals being released from prison.

He said Mrs. Clinton’s agenda was “to release the violent criminals from jail,” freeing them to roam the streets and put “innocent Americans at risk.”

He even tried out a new epithet for Mrs. Clinton: “heartless Hillary.”

Calling Mrs. Clinton and her husband, former President Bill Clinton, “heartless hypocrites,” he dared them to “let their bodyguards immediately disarm,” an apparent reference to their Secret Service protection.

“Let’s see how good they do,” Mr. Trump said. “Let’s see how they feel walking around without their guns and their bodyguards. In the meantime, nobody else can have the guns, right?”