Donald Trump is facing fresh accusations of racism after launching a Twitter tirade at the weekend against Elijah Cummings, a prominent minority Democratic congressman, and referring to Baltimore, in the latter’s majority black district, as a “rodent-infested mess”.

The president’s comments ignited yet another firestorm over race issues in Washington, just weeks after he was widely condemned for attacking four congresswomen of color, in what appears to be a deliberate strategy going into the 2020 election.

Trump, who rose to political prominence by falsely insisting Barack Obama was born in Kenya, has a long history of targeting minorities and people of color.

Some researchers have questioned if the divisive approach will work, particularly as polling finds that a growing majority of Americans believe Trump has made race relations worse.

Here are prominent political leaders of color that Trump has attacked in personal ways:

Al Sharpton

Trump on Monday directed his ire at the Rev Al Sharpton, a longtime black activist who earlier in the day shared a photo of himself en route to Baltimore from his base in New York City.

Stating that he had known Sharpton for 25 years, Trump went on to attack the the civil rights advocate, who is ally keenly sought by Democratic 2020 candidates, as someone who “hates whites and cops”.

“He would ask me for favors often. Al is a con man, a troublemaker, always looking for a score,” Trump tweeted.

Sharpton responded with a photo featuring himself, Trump, the Rev Jesse Jackson and soul great James Brown at a 2006 conference, adding Trump told him at the time he “respects my work”.

“Different tune now,” Sharpton noted.

The Squad

Trump tweeted this month that four congresswomen of color – who are all US citizens – should “go back” to where they “came from”. The tweetswere directed at Alexandria Ocasio-Cortez of New York, Ilhan Omar of Minnesota, Rashida Tlaib of Michigan and Ayanna Pressley of Massachusetts, and were widely decried as racist.

Trump nonetheless doubled down and singled out the four freshmen Democrats, known as “the Squad”, at a rally in North Carolina. His criticism of Omar, who came to America as a Somali refugee and is a naturalized citizen, prompted chants of “send her back” from the crowd.

Omar described the episode as “a defining moment in American history”.

Maxine Waters

Maxine Waters, a congresswoman from California, has been a frequent target of Trump’s, amid her fierce criticism of his administration. Trump has repeatedly derided Waters, a member of the congressional black caucus, as “crazy” and an “extraordinarily low-IQ person”.

Maxine Waters has been a frequent target for Trump. Photograph: Erin Scott/Reuters

The feud between the two escalated last year when Waters encouraged supporters to “show up” and protest against Trump administration officials in public places, be it restaurants, stores or gas stations. Those comments drew a rebuke from Democratic Party leaders, who pushed back on “harassing” political opponents.

LeBron James and Don Lemon

Last year, Trump mocked the intelligence of NBA superstar LeBron James and CNN host Don Lemon – both prominent men of color – after James criticized Trump in an interview with Lemon.

“LeBron James was just interviewed by the dumbest man on television, Don Lemon,” Trump wrote. “He made LeBron look smart, which isn’t easy to do.”

James, whose interview focused on his work for at-risk children and inner city youngsters, said Trump was trying to use sport to divide the country. James’ comments were a reference to Trump’s attacks on sportspeople of color who have kneeled during the US national anthem to draw attention to police brutality and criminal justice reform.

Andrew Gillum

During the 2018 midterm elections, Trump went after Florida gubernatorial candidate Andrew Gillum in what opponents saw as racially loaded language. Gillum, who was vying to become the state’s first black governor, had been serving as the mayor of Tallahassee.

Without evidence, Trump labeled Gillum a “thief” and accused him of overseeing one of the “most corrupt cities” in the country. Trump, who campaigned for Ron DeSantis, the Republican who went on to win the race despite a controversial attack on Gillum, also said Florida would become “a crime-ridden, overtaxed mess” if Gillum were elected governor.

Barack Obama

Trump’s attacks on Barack Obama have been wide-ranging and a constant fixture of his political career. And many of them have invoked the former president’s race, or made a thinly veiled attempt to cast the nation’s first black president as ‘foreign’.

Trump was among the most vocal proponents of conspiracy theories around Obama’s birthplace. He repeatedly called on Obama, who was born in Hawaii, to release his birth certificate. When Obama did so, Trump falsely claimed it was a “fraud”.

Trump also routinely linked Obama, a Christian, to Islam, in a bid to stoke fears around his faith. During the 2016 election he referred to Obama as the “founder of Isis” and, years ago, Trump complained about crime in Baltimore and blamed “our great African American president”.