A former advisor to US presidents George H.W. Bush and Ronald Reagan has highlighted the biggest challenge facing Donald Trump as he turns his attention to the battle for the White House.
After a sometimes bitter and divisive campaign for the Republican nomination, Trump has now secured enough support to clinch the nomination at the party's convention in July.
Using a 'shoot from the hip' approach, he has made numerous controverisal statements, from mocking the wife of a rival to saying he would build a wall across the border of Mexico to keep out immigrants.
According to Mary-Jo Jacobi, an advisor to president Reagan and assistant secretary of commerce under George Bush senior, Trump now has to juggle this approach with "dialling back the rhetoric" to appear more presidential.
"It's a tough pivot for him, because it is what has gotten him this far," she told Julia Hartley-Brewer.
"His challenge is to keep his authenticity, his honesty, and yet start to sound more presidential.
“The art of politics is the art of compromise.
"He's been successful at that in business, presumably he can be successful at that in politics, if he just turns down and dials back that rhetoric a little bit.
"He's rounding up the establishment, which will be important, and he is looking like he will start taking the advice of people who have walked this road before.
"I have to admit I'm surprised [at Trump securing the number of delegates required to clinch the Republican nomination]," she said.
"He has worked the field and carried it through to what appears to be the end of the road.
"He will continue to shake things up between now and July. It'll be an interesting thing to watch."