Dan Gilbert, Cleveland Cavaliers, LeBron James
Jun 22, 2016; Cleveland, OH, USA; Cleveland Cavaliers owner Dan Gilbert speaks to the crowd during the Cleveland Cavaliers NBA championship celebration in downtown Cleveland. USA TODAY Sports / Ken Blaze

Dan Gilbert, the principal owner of the Cleveland Cavaliers, was bombarded with "vile, disgusting, racist" voicemails in the aftermath of LeBron James calling US President Donald Trump "a bum" over Twitter. James was echoing his support to the Golden State Warriors after Trump withdrew an invitation to the White House for the reigning NBA champions.

During a guest appearance on CNBC's "Squawk Box," Gilbert revealed that his phone was filled with vile messages. "I received voicemails after LeBron tweeted that were some of the most vile, disgusting, racist (messages). There's an element of racism that I didn't even realize existed in this country this much."

Spearhead by LeBron James, the NBA has taken an anti-Donald Trump stance since the onset. After coaches such as Steve Kerr, Gregg Popovich and Stan Van Gundy slammed the voters in the country to electing Trump to presidency, Warriors All-Stars Stephen Curry and Kevin Durant flat out refused to travel to the White House for the customary champions' visit.

Sporting world turns on Donald Trump

A few days later, the NFL stood up to Trump after the US President encouraged owners to "fire players" that protested the national anthem. Since those controversial remarks, athletes and sporting leagues the world over have united to voice their displeasure over Trump's leadership and decision-making.

Gilbert revealed that he never informed James, his franchise superstar, about the messages. "The thing is, I mean, some of the most disgusting things I've ever heard people say. And you could hear it in their voice -- the racism. It wasn't even really about the issue, and that's what really got me, because they went to who they really are, some of them."

Incidentally, Gilbert has been associated with Trump in the past after his firm, Quicken Loans, donated a sum of US$750,000 (AU$958,000) to the president's swearing-in party. In fact, Gilbert also referred to Trump as "a great friend." However, Gilbert issued a statement this week to clarify his political stance.

"Our interests are in the policies at the federal level, and not the politics surrounding the elections. We have often supported both political parties in the same election so that we have the ability to impact positive change, regardless of who occupies the offices," Gilbert said while encouraging LeBron James and other members of the Cleveland Cavaliers to exercise their freedom of speech.