Former Trump Adversary Javier Palomarez Joins Administration's Diversity Coalition

— -- President-elect Donald Trump's national diversity coalition has a new -- and previously adversarial -- adviser: U.S. Hispanic Chamber of Commerce president Javier Palomarez.

ABC News has confirmed that Palomarez -- whose organization endorsed GOP candidate John Kasich during primary season and Hillary Clinton for the general election -- has accepted the Trump transition team's offer.

But the pair have butted heads in the past.

In October 2015, ABC News reported that then-GOP presidential front-runner Trump backed out of the USHCC's Presidential Candidate Q&A Session after the organization said Trump found out he would be asked about his plans to deport undocumented immigrants.

Palomarez had personally met with Trump in September 2015 to secure the date for the Q&A, the organization said at the time.

According to the USHCC, which represents Hispanic small business owners, Trump didn't like the format and worried about the questions.

"Mr. Trump was unwilling to abide by the terms and conditions of the USHCC's Presidential Candidate Q&A Series -- the same rules that all participants have previously followed," Palomarez said in a statement at the time. "The USHCC refused to change the format of the forum, show any favoritism, exclude any issues or topics, or grant any immunity from objective scrutiny of his policies."

But the Trump campaign alleged that the USHCC requested Trump join the chamber "for a fee amounting to between $25,000 and $2 million, which Mr. Trump refused to do."

That only intensified the rift between Trump and Palomarez's organization.

The USHCC said it never raised the subject of Donald Trump joining the association.

"Trump's statement on sponsorship is a lie," Palomarez told ABC News at the time. "He asked if we would consider [Trump National] Doral [Hotel] for our Miami convention. We said no. We’ve also severed business relations with him indefinitely."

ABC News' Serena Marshall and Jim Avila contributed to this report.