Ahead of campaigning in Ohio, President Donald Trump unleashed a withering attack on the state’s favourite son, savaging basketball star LeBron James in a late-night tweet that derided the intelligence of one of the nation’s most prominent African-American men.

Melania Trump’s spokeswoman quickly distanced the first lady from the tweet, saying in a statement that it appeared James was “working to do good things on behalf of our next generation” and that she would be open to visiting his new school for at-risk children.

Trump blasted James late on Friday after an interview aired with CNN anchor Don Lemon in which he deemed Trump divisive.

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

James, who campaigned for Hillary Clinton, did the CNN interview from the public school he opened, called the “I Promise” school. Every student receives free tuition, as well as free food, a uniform and even a free bike.

As an afterthought, Trump also weighed in on the growing debate over who is the greatest NBA player of all time, James or Michael Jordan, by writing “I like Mike!”

Lebron James was just interviewed by the dumbest man on television, Don Lemon. He made Lebron look smart, which isn’t easy to do. I like Mike!

— Donald J. Trump (@realDonaldTrump) August 4, 2018

Although James has long been a Trump critic, calling the president “U bum” in a 2017 tweet, the tweet was Trump’s first attack on the player, who just opened up a school for underprivileged children in his hometown of Akron.

LeBron James was an ardent supporter of Hillary Clinton during the 2016 presidential race. Photo: AP/Phil Long

The tweet came hours before Trump travelled to Columbus, Ohio, for a rally north of town in support of the Republican in a special US House election on Tuesday.

Once in Ohio Trump stayed away from the controversy and didn’t mention James as he hammered away at Democrats and other favourite targets.

Many former and current professional athletes, including Jordan, jumped to James’ defence.

“I support LeBron James. He’s doing an amazing job for his community,” Jordan said in a statement to Associated Press through his representative via text.

Trump has long denounced the media – CNN in particular – and rarely lets a slight go unnoticed. But the attack on James, who was being interviewed by another black man, to some resembled a racial dog whistle.

Mr Trump routinely deems Democrat Maxine Waters of California, who is also black, as “low IQ” – an insult he repeated during the Ohio rally on Saturday night.

Trump has repeatedly been questioned about his views on race, from deeming many Mexican immigrants “rapists” during his campaign kickoff speech for the Republican presidential nomination to placing blame on “both sides” for the violent clash between white supremacists and counterprotesters in Charlottesville, Virginia, a year ago.

-AAP