President Trump attacked the Rev. Al Sharpton on Monday as “a con man” and someone who “Hates Whites & Cops,” just hours before Sharpton held a news conference in Baltimore to decry Trump’s derogatory weekend tweets directed at the city and an African American congressman.

Sharpton, a former Democratic presidential candidate and MSNBC talk-show host, appeared in Baltimore alongside Michael Steele, who formerly chaired the Republican National Committee and served as Maryland’s lieutenant governor.

At the event, held at a Baltimore church, Sharpton said Trump had attacked the city and Rep. Elijah Cummings (D-Md.) in “the most bigoted and racist way.”

“He has a particular venom for blacks and people of color,” Sharpton said of Trump.

Steele, the first African American elected statewide in Maryland, criticized Trump for “reprehensive comments” and invited him to come to Baltimore.

“Put the tweet down brother, and show up,” Steele said.

In tweets beforehand, Trump said he had known Sharpton for 25 years. He said the two “always got along well” and attended boxing matches together.

“He would ask me for favors often,” Trump said. “Al is a con man, a troublemaker, always looking for a score. Just doing his thing. Must have intimidated Comcast/NBC. Hates Whites & Cops!”

Lawmakers on July 28 discussed President Trump's tweets targeting Rep. Elijah E. Cummings (D-Md.) and the Baltimore district Trump called "rodent infested." (Jhaan Elker/The Washington Post)

Sharpton’s news conference came two days after Trump criticized Baltimore as a “rodent infested mess” where “no human being would want to live” and attacked Rep. Elijah E. Cummings (D-Md.), who represents part of the city. Cummings chairs the House Oversight Committee, which has been holding an array of hearings critical of Trump administration practices.

Sharpton responded Monday morning on Twitter by sharing a photograph of Trump attending a 2006 conference hosted by Sharpton’s organization, the National Action Network. The photo also included singer James Brown and civil rights leader Jesse Jackson.

“Trump at NAN Convention 2006 telling James Brown and Jesse Jackson why he respects my work. Different tune now,” Sharpton wrote.

Trump soon responded on Twitter, saying that Sharpton would “always ask me to go to his events” as “a personal favor.”

“Seldom, but sometimes, I would go. It was fine,” Trump said.

Sharpton later continued the back-and-forth on Twitter, writing: “Trump says I’m a troublemaker & con man. I do make trouble for bigots. If he really thought I was a con man he would want me in his cabinet.”

Trump also renewed his attacks on Baltimore and Cummings on Monday, asserting in a tweet that the city of more than 600,000 people “has the worst Crimes Statistics in the Nation.”

“25 years of all talk, no action!” Trump wrote. “So tired of listening to the same old Bull...Next, Reverend Al will show up to complain & protest. Nothing will get done for the people in need. Sad!”

Steele also spoke out about Trump over the weekend, raising a question in a tweet about “how much more of Trump’s incessant whining, tweeting, bullying, & racism are we willing to put up with.”

Trump launched his attacks on Cummings two weeks after he started taking aim at a group of four liberal minority congresswomen known on Capitol Hill as “the Squad.”

In the first of his tweets attacking the freshman lawmakers, he said they should “go back” to the “totally broken and crime infested places from which they came” — remarks that drew a rebuke from the House.

Only one of the four women — Rep. Ilhan Omar (D-Minn.), a Somali refu­gee who became a U.S. citizen in 2000 — was born outside the United States. The others — Reps. Alexandria Ocasio-Cortez (N.Y.), Ayanna Pressley (Mass.) and Rashida Tlaib (Mich.) — were born in the United States.

In another tweet Monday, Trump referenced the four lawmakers again.

“If the Democrats are going to defend the Radical Left ‘Squad’ and King Elijah’s Baltimore Fail, it will be a long road to 2020,” he said.

Trump’s advisers have concluded that the overall message sent by such attacks is good for the president among his political base — resonating strongly with the white working-class voters he needs to win reelection in 2020.

Sharpton also saw a political motive in Trump’s attacks. During a call Monday morning into MSNBC’s “Morning Joe,” he said, “I think this is Trump getting ready for reelection.”

Later Monday morning, Trump struck a more hopeful note about Baltimore and suggested that the city’s leaders call him.

“The fact is, Baltimore can be brought back, maybe even to new heights of success and glory, but not with King Elijah and that crew,” he said. “When the leaders of Baltimore want to see the City rise again, I am in a very beautiful oval shaped office waiting for your call!”

Toluse Olorunnipa and Ashley Parker contributed to this report.