James is considered by many to be the greatest player in basketball history, rivaled by Chicago Bulls legend Michael Jordan.
The debate over who is better has raged on for years and has passionate supporters arguing each side.
That suggests Trump was referring to Jordan at the end of his tweet. A 1990s Gatorade commercial opens with the slogan 'Be like Mike'.
On Monday, James spoke at lengths about the President, race and politics in a wide-ranging interview which aired just hours after opening his new I Promise School in Akron, Ohio.
His commitment to children that were falling behind in school, vowing to use the new school to help them not only catch up with their peers, but to excel, was put in direct contrast to several Trump government policies seen to disadvantage young people as social media users erupted over the President's tweet.
Many tweeted both about separating children from their parents at the border, and of changes to how college students are treated and how their education is paid for.
"This week, LeBron opened a school for hundreds of at-risk kids while Donald Trump's education secretary attempts to undo college loan forgiveness for students who were 'knowingly deceived' by their schools, and rolls back Obama-era guidelines on discrimination in schools," Harrison Faigen, an NBA writer, posted.
"LeBron puts children through school. Trump puts children in cages," his colleague Joseph Flynn wrote.
Others chose to point out Trump seemed to have little issue with white athletes, and had also publicly slammed Stephen Curry, LaVar Ball, Colin Kaepernick, and Marshawn Lynch.
"Trump has only called Don Lemon & Lebron James 'dumb' and he repeatedly refers to Maxine Waters as 'low IQ'," one man wrote.
"Pop quiz - Besides all being smarter & better in every way than he is, what else do they have in common?
"A) Donald Trump. Is. A. Racist. Pig."
Some also speculated Trump's attack came as LeBron had moved to California, which is not a swing state like Ohio, where he previously lived, unscathed by the President's wrath.
In 2013, Trump said LeBron was 'a great player and a great guy'.
Even POTUS' supporters found the tweet to be in bad taste. 'I support you but this is unacceptable, you need to apologize immediately,' wrote Wesley Cantrell.
In his interview with Lemon, LeBron described how both athletics and education were high priorities for the young students at his new school, and lamented the idea of politics interfering with sports.
"When you're part of sports, it brings so much camaraderie and so much fun. We are in a position right now, in America more importantly, where this whole race thing has taken over,' he said.
"I believe our president is trying to divide us... he is, he's dividing us and what I have noticed over the last few months is that he's kind of used sport to divide."
James said Trump is creating a wedge by using situations like NFL player Colin Kaepernick kneeling during the anthem and 'uninviting' NBA star Steph Curry to the White House.
He also said he might consider running for office if someone said to him he was the only person and that Trump would win if he didn't step up.
