President Trump targeted Maryland Rep. Elijah Cummings on Twitter for a second day Sunday — as the tweets brought rebukes from Democrats and a defense from a top White House adviser who claimed the president was simply punching back.

“Congressman Elijah Cummings has done a very poor job for his district and the City of Baltimore,” the president wrote, adding that the Democrats “always play the Race Card” and that Cummings “has failed badly.”

The president resumed tweeting about Cummings, the chairman of the House Oversight Committee, after a string of tweets on Saturday in which he described the congressman as a “brutal bully” and his Maryland district as “rat and rodent infested.”

On Sunday, Trump referred to Cummings, who is African-American, as “racist” without any explanation — and suggested he “focus more of his energy on helping the good people of his district and Baltimore itself.”

Cummings didn’t respond to the new tweets on Sunday, but on Saturday he said, “I go home to my district daily. Each morning, I wake up, and I go and fight for my neighbors.”

Sen. Bernie Sanders, a Democratic presidential candidate, called Cummings “one the most decent and outstanding members of the House of Representatives.”

“It’s unbelievable that we have a president of the United States who attacks American cities, who attacks Americans, who attacks somebody who is a friend of mine,” Sanders said on CNN’s “State of the Union.”

But acting White House Chief of Staff Mick Mulvaney said Trump is just retaliating against Cummings for criticizing acting Department of Homeland Security Secretary Kevin McAleenan earlier this month over the administration’s family-separation policy and conditions at the southern border.

“What this is about, though, is the president fighting back against what he saw as being illegitimate attacks about the border,” Mulvaney said on “Fox News Sunday.”

Rep. Rashida Tlaib, who was among four minority Democratic congresswomen attacked by Trump this month, said the president continues to trash American cities.

“Our president has a hate agenda,” she said on CNN​. “He doesn’t have a policy agenda. That’s what he falls down on.”

Rep. Will Hurd, the only African-American Republican in the House, said Trump’s tweets about Cummings aren’t the same as the “go back” postings about Tlaib and her three colleagues — Reps. Alexandria Ocasio-Cortez, Ilhan Omar and Ayanna Pressley.

“I wouldn’t be doing those. I wouldn’t be tweeting this way,” the Texan said on ABC’s “This Week.”

“Chairman Cummings is someone I worked with closely on all kinds of legislation,” Hurd added. “He is someone that cares passionately about his community and has been working tirelessly his entire adult life on behalf of his country and his community.”