Philadelphia District Attorney Larry Krasner responded Wednesday to President Donald Trump’s attacks against him the night before, inviting the president to come discuss criminal justice reform and casting Trump’s comments as a sign of political weakness.

Trump, who headlined a rally Tuesday in Hershey, Pa., criticized Philadelphia’s “sanctuary city" policy and called Krasner “the worst district attorney,” wrongly accusing him of letting killers “out almost immediately.”

“Get yourselves a new prosecutor,” Trump told the crowd.

Krasner fired back after a news conference about his office’s decision to drop charges against an 18-year-old who prosecutors say accidentally shot and killed his twin brother.

“He’s standing somewhere in the middle of Pennsylvania with a typical group of supporters and he is blowing a dog whistle," Krasner said. "He is rallying rural sections of the state to despise everything that Philadelphia is — a city of immigrants, a city that is very diverse, and a city that rejected him by 85% of the vote last time he ran. He’s doing so because he is afraid. He’s doing so because he is politically weak.”

Krasner argued that increased voter turnout in Philadelphia since 2016, including when he ran for DA in 2017, frightens Trump in a state critical to his reelection. He said the call-out would only mobilize more Democrats here.

“He gave Philadelphians so many more reasons to go on their social media accounts today and encourage their friends to vote and contact every new 18-year-old they know to get registered,” Krasner said.

“President Trump, Philadelphia’s got something for you — we are going to make sure that you lose Pennsylvania and we are going to make sure you do not return for a second term," Krasner added. "You are not going to undermine and destroy our democracy and you are not going to stop the good and progressive district attorneys around this country.”

Krasner, one of a new crop of progressive prosecutors in the country, has repeatedly feuded with Trump-appointed U.S. Attorney William McSwain and with John McNesby, president of Philadelphia’s police union. McNesby visited the White House last week and met with Trump, in part to complain about Krasner.

It’s not the first time Trump has blasted someone his supporters might not be familiar with (he was speaking about 100 miles west of Philadelphia). He has a habit of going after all sorts of people, from Democrats in Congress to his own FBI director. In the same speech in which he attacked Krasner, Trump also took shots at potential Democratic opponents such as Massachusetts Sen. Elizabeth Warren; Mayor Pete Buttigieg of South Bend, Ind., and former Vice President Joe Biden.

Challenging Trump’s own vision of criminal justice, Krasner said the president would “almost certainly be impeached,” and questioned some of the pardons he’s issued as president. He invited Trump to come meet with him while in Philadelphia for the Army-Navy Game on Saturday.

“Please, come to Philadelphia. Let us have a robust discussion about criminal justice reform,” he said. “You and me, let’s go.”

Staff writer Julie Shaw contributed to this article.