As senior Republican officials tucked into oysters and shrimp at a Florida resort, the man before them unveiled a PowerPoint presentation setting out how Donald Trump would win the party nomination.

“The part that he's been playing is now evolving into the part that you've been expecting. The negatives will come down, the image is going to change,” said Paul Manafort, who recently took up a senior role in Mr Trump's campaign.

The message was simple: the bombastic character who has courted outrage to appeal to the party base was, in fact, a calculating candidate playing a role. In the weeks to come, he would take on a new persona, that of president in waiting as he pivoted towards a general election against Hillary Clinton.

Some analysts have already detected a difference in tone as Mr Trump's divisive campaign tries to broaden its appeal.

Mr Manafort, who was hired by the Republican front-runner last month, knows a thing or two about rebranding strongmen.

The Washington operative has an extraordinary past roster of clients, including Ferdinand Marcos, the dictator of the Philippines, Unita rebels in Angola and Siad Barre, the military ruler of Somalia until his downfall in 1991.