Former Republican candidate Ben Carson has described his one-time rival, Donald Trump as “a very intelligent man who cares deeply about America”.
In a news conference on Friday at the real estate tycoon’s Mar-a-Lago club in Palm Beach, Florida, the retired neurosurgeon said: “There’s two different Donald Trumps.
“There’s the one you see on the stage, and there’s the one who’s very cerebral, sits there and considers things very carefully.”
The endorsement comes ahead of what could be a decisive week in the party’s presidential nomination race.
Carson said he had “buried the hatchet” with the billionaire over their scathing campaign clashes. On his Facebook page, Carson provided detailed explanation about his reasons for supporting Trump.
Mr Trump, 69, mentioned during Thursday night’s televised Republican debate that Mr Carson would be backing him.
Responding to questions about past personal attacks on Friday, Mr Trump shrugged and said: “It’s a tough business, politics” and described Mr Carson as a “special, special person”.
Mr Carson, 64, dropped out of the race last week after failing to win a single primary contest, though he remains popular with evangelical voters.
He is the second former Republican presidential candidate to officially back Mr Trump, following New Jersey Governor Chris Christie’s approval last month.
The latest endorsement is a blow to Texas Senator Ted Cruz, who has been in a tug-of-war with Mr Trump for the evangelical vote.
The announcement has generated conflicting reactions on Twitter with some supporting the idea and others recalling their scathing personal attacks on one each other.
The pairing may seem odd to some people, but for the two Republicans, It’s about uniting against a common enemy, Democrat, Hillary Clinton.