President Donald Trump, after a weekend of attacks on Rep. Elijah Cummings, D-Md., and his Baltimore-area district, began Monday by blasting the Rev. Al Sharpton as someone who "hates whites and cops."

"I have known Al for 25 years. Went to fights with him & Don King, always got along well. He 'loved Trump!'" Trump tweeted in response to Sharpton posting a photo of him en route to Baltimore. "He would ask me for favors often. Al is a con man, a troublemaker, always looking for a score. Just doing his thing. Must have intimidated Comcast/NBC. Hates Whites & Cops!"

Sharpton is the host of "PoliticsNation" on MSNBC. He responded to Trump with a photo of the president speaking to the Rev. Jesse Jackson, musician James Brown and Sharpton at his 2006 National Action Network conference and said Trump told him at the time he "respects my work."

"Different tune now," Sharpton added.

Trump at NAN Convention 2006 telling James Brown and Jesse Jackson why he respects my work. Different tune now. pic.twitter.com/mvNQmPdLUh — Reverend Al Sharpton (@TheRevAl) July 29, 2019

Trump then sent another tweet about Sharpton, calling him a "conman" who "would always ask me to go to his events."

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

Sharpton fired back, saying if Trump "really thought I was a con man he would want me in his cabinet."

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. — Reverend Al Sharpton (@TheRevAl) July 29, 2019

Speaking with MSNBC on Monday morning, Sharpton said Trump "should not continue to try and sell this racist behavior, to try and make the country more divided for his own political gain." Sharpton called Trump's tweets aimed at Cummings and Baltimore "absolutely horrible."

"First of all, part of Congressman Cummings' district is very stable," Sharpton said. "It is probably the most educated and economically mobile African American district that we know in the Northeast if not the country. But his whole stereotyping of them is racist."

After Trump called Sharpton a "troublemaker," Sharpton said, "I am a 'troublemaker ... I am going to make trouble any time racists and bigots move around in any way, shape or form, including the president."

Sharpton, who said he has known Trump for decades, noted that the president didn't always think of him as a con man.

"He's playing the race-baiting crowd," Sharpton said, adding that Trump called him after the 2016 election and invited him to Mar-a-Lago, his Florida resort. "This is race baiting at its best. This is Donald Trump playing the race card, and it is a shame and it is a sham."

Over the weekend, Trump called Cummings' 7th Congressional District in Maryland "a disgusting, rat and rodent infested mess" and said that "no human being would want to live there." He later called Cummings, who is black, a "racist."

Trump continued to hit Cummings on Monday morning, saying that if "Democrats are going to defend the Radical Left 'Squad' and King Elijah's Baltimore Fail, it will be a long road to 2020."

"The squad" is a group of four freshmen House Democrats Trump has attacked on Twitter, saying the four women of color should "go back" to where they came from instead of criticizing his administration. All four of the women — Reps. Rashida Tlaib of Michigan; Ayanna Pressley of Massachusetts; Alexandria Ocasio-Cortez of New York; and Ilhan Omar of Minnesota — are U.S. citizens, and only Omar was born outside the U.S. In response, Cummings told ABC's "This Week" on its July 21 show that he had "no doubt" that Trump is a racist.

Top Democrats as well as prominent Baltimore residents swiftly rebuked Trump's comments as "racist," "disgraceful" and "dangerous." Trump on Sunday responded to the criticism by accusing Democrats of playing the "race card" and said there was "nothing racist" about his remarks.

Cummings himself responded to the president's barbs on Saturday, tweeting that he is in his district every day.

"Each morning, I wake up, and I go and fight for my neighbors," Cummings said. "It is my constitutional duty to conduct oversight of the Executive Branch. But, it is my moral duty to fight for my constituents."

Some Republicans were critical of the president's tweets, too. Former New Jersey Gov. Chris Christie, a longtime Trump ally, said during an appearance on "This Week" he thought Trump's tweets were "a bad idea." Rep. Will Hurd of Texas told the show: "I wouldn’t be tweeting this way."

The altercation comes days after Cummings' committee voted to subpoena personal emails and texts of top White House aides, including Trump's daughter Ivanka Trump and her husband, Jared Kushner, who are both prominent White House staffers. It also followed a press conference after former special counsel Robert Mueller's congressional testimony at which Cummings said he is "begging the American people to pay attention to what is going on" regarding the president and his associates.