Donald Trump called Elijah Cummings a “racist” on Sunday after describing the senior Democratic congressman of colour’s district as a “rat and rodent infested mess”.

“If racist Elijah Cummings would focus more of his energy on helping the good people of his district, and Baltimore itself, perhaps progress could be made in fixing the mess that he has helped to create over many years of incompetent leadership,” the president wrote on Twitter. “His radical ‘oversight’ is a joke!”

Mr Trump continued escalating his attacks over the weekend against Mr Cummings, going so far as to retweet a reportedly Islamaophobic activist who described the congressman’s majority-black city of Baltimore as a “s***hole”.

The president also attempted to defend himself in the wake of growing backlash for his incendiary comments, writing in a separate tweet, “There is nothing racist in stating plainly what most people already know, that Elijah Cummings has done a terrible job for the people of his district, and of Baltimore itself.”

But he could not push back the growing tide of anger felt nationwide for launching attacks at a growing list of minority politicians and frequently using the term "infested" to describe places with predominantly black populations like Baltimore and African countries.

Trump 2020 launch: Fascist Proud Boys, baby blimps and Uncle Sam Show all 30 1 /30 Trump 2020 launch: Fascist Proud Boys, baby blimps and Uncle Sam Trump 2020 launch: Fascist Proud Boys, baby blimps and Uncle Sam Members of the Proud Boys, a fascist group, jeer at anti-Trump protesters outside of the president's 2020 campaign launch in Orlando, Florida Getty Trump 2020 launch: Fascist Proud Boys, baby blimps and Uncle Sam A supporter dressed as Uncle Sam poses at Uncle Sam Reuters Trump 2020 launch: Fascist Proud Boys, baby blimps and Uncle Sam A baby blimp rears its head amidst a group of anti-Trump protesters outside the president't campaign launch in Orlando, Florida Getty Trump 2020 launch: Fascist Proud Boys, baby blimps and Uncle Sam President Trump addresses supporters at the launch event of his 2020 election campaign in Orlando, Florida Reuters Trump 2020 launch: Fascist Proud Boys, baby blimps and Uncle Sam Proud Boys have adopted Fred Perry polo shirts as their uniform and many members have the name of the group tattooed on their arms Getty Trump 2020 launch: Fascist Proud Boys, baby blimps and Uncle Sam A line of police officers separate opposing groups of protesters outside the launch of President Trump's 2020 campaign launch Getty Trump 2020 launch: Fascist Proud Boys, baby blimps and Uncle Sam A protester hits a Trump punching bag during a protest outside Trump's 2020 campaign launch in Orlando, Florida Getty Trump 2020 launch: Fascist Proud Boys, baby blimps and Uncle Sam Twin Trump supporters pose for a photo at the president's 2020 campaign launch in Orlando, Florida Reuters Trump 2020 launch: Fascist Proud Boys, baby blimps and Uncle Sam A protester dressed as a caricature of Donald Trump stands outside the president's 2020 campaign launch in Orlando, Florida AP Trump 2020 launch: Fascist Proud Boys, baby blimps and Uncle Sam A Trump supporter faces off against a protester outside the president's campaign launch in Orlando, Florida AFP/Getty Trump 2020 launch: Fascist Proud Boys, baby blimps and Uncle Sam A Proud Boy shouts across the police line at anti-Trump protesters outside the president's campaign launch in Orlando, Florida Getty Trump 2020 launch: Fascist Proud Boys, baby blimps and Uncle Sam A Trump supporter poses for a photo at the president's 2020 campaign launch in Orlando, Florida Reuters Trump 2020 launch: Fascist Proud Boys, baby blimps and Uncle Sam A Proud Boy jeers at anti-Trump protesters who are separated from the president's supporters by a police line outside the president's campaign launch in Orlando, Florida Getty Trump 2020 launch: Fascist Proud Boys, baby blimps and Uncle Sam A man dressed as Uncle Sam poses at President Trump's 2020 campaign launch in Orlando, Florida Reuters Trump 2020 launch: Fascist Proud Boys, baby blimps and Uncle Sam An anti-Trump protester faces off against a supporter outside the president's campaign launch in Orlando, Florida AFP/Getty Trump 2020 launch: Fascist Proud Boys, baby blimps and Uncle Sam Members of the Proud Boys, a fascist group, jeer at anti-Trump protesters outside of the president's 2020 campaign launch Getty Trump 2020 launch: Fascist Proud Boys, baby blimps and Uncle Sam A child holds a 2020 US "dollar bill" that features Donald Trump's face at the president's 2020 campaign launch EPA Trump 2020 launch: Fascist Proud Boys, baby blimps and Uncle Sam Anti-Trump protesters rally outside the president's 2020 campaign launch in Orlando, Florida Getty Trump 2020 launch: Fascist Proud Boys, baby blimps and Uncle Sam Anti-Trump protesters rally outside the president's 2020 campaign launch in Orlando, Florida Getty Trump 2020 launch: Fascist Proud Boys, baby blimps and Uncle Sam Numerous baby Trump balloons are raised in protests outside of the president's 2020 campaign launch in Orlando, Florida Getty Trump 2020 launch: Fascist Proud Boys, baby blimps and Uncle Sam A supporter wears a T-shirt depicting Trump as a hero at the president's 2020 campaign launch in Orlando, Florida Reuters Trump 2020 launch: Fascist Proud Boys, baby blimps and Uncle Sam President Trump addresses supporters at the launch event of his 2020 election campaign in the Amway Centre in Orlando, Florida AFP/Getty Trump 2020 launch: Fascist Proud Boys, baby blimps and Uncle Sam An anti-Trump protester calls for the president to be impeached outside the launch event for his 2020 campaign launch in Orlando, Florida Getty Trump 2020 launch: Fascist Proud Boys, baby blimps and Uncle Sam Supporters of Donald Trump face off against protesters outside of the president's 2020 campaign launch in Orlando, Florida AP Trump 2020 launch: Fascist Proud Boys, baby blimps and Uncle Sam A baby blimp rises behind a group of anti-Trump protesters outside the president's campaign launch in Orlando, Florida AP Trump 2020 launch: Fascist Proud Boys, baby blimps and Uncle Sam A supporter dressed as Uncle Sam poses at President Trump's 2020 campaign launch in Orlando, Florida AP Trump 2020 launch: Fascist Proud Boys, baby blimps and Uncle Sam A member of the Proud Boys, a fascist group, holds a sign up outside of the president's 2020 campaign launch in Orlando, Florida AFP/Getty Trump 2020 launch: Fascist Proud Boys, baby blimps and Uncle Sam A supporter bears a Trump flag at the president's 2020 campaign launch in Orlando, Florida Reuters Trump 2020 launch: Fascist Proud Boys, baby blimps and Uncle Sam Protesters hold baby Trump balloons in the rally outside of the president's 2020 campaign launch in Orlando, Florida Getty Trump 2020 launch: Fascist Proud Boys, baby blimps and Uncle Sam An anti-Trump protester holds a sign accusing the president of being a traitor Getty

Earlier this month, Mr Trump hurled insults online at four Democratic congresswomen of colour who he told to "go back" to their countries, despite all but one having been born in the United States. The tweets reflected a racist trope well-known to the country's citizens of colour, who recalled their own experiences of being told to go back to where they came from after the president's comments.

Top Democrats on Capitol Hill have rebuked the president's latest "racist attacks" against Mr Cummings.

Mr Cummings "is a champion in the Congress and the country for civil rights and economic justice, a beloved leader in Baltimore, and deeply valued colleague," House Speaker Nancy Pelosi said in a tweet.

"We all reject racist attacks against him and support his steadfast leadership," she wrote, adding the hashtag #ElijahCummingsIsAPatriot.

Mr Cummings, the chairman of the House Oversight Committee, has steadily investigated the president’s financial dealings and has sought to obtain the president’s financial records.

On Saturday, he responded to the president in a tweet: “Mr. President, I go home to my district daily. Each morning, I wake up, and I go and fight for my neighbors.”

“It is my constitutional duty to conduct oversight of the Executive Branch,” he wrote. “But, it is my moral duty to fight for my constituents.”

Support free-thinking journalism and attend Independent events

The president also insinuated Ms Pelosi was the one with racial issues rather than himself, writing on Saturday, “Someone please explain to Nancy Pelosi, who was recently called racist by those in her own party, that there is nothing wrong with bringing out the very obvious fact that Congressman Elijah Cummings has done a very poor job for his district and the City of Baltimore.”