PROSPECT OF CONTESTED CONVENTION

Republican strategist Ron Bonjean said the hiring of Wiley and, two weeks ago, of delegate specialist Paul Manafort suggest that Trump is preparing for a contested convention in July should he not win outright the 1,237 delegates needed for the Republican presidential nomination.

"Without having good people on your team who understand how to navigate those waters, you're in big trouble," he said.

The steps point to a new phase of Trump's campaign after vulnerabilities were exposed when he was beaten in Wisconsin by Cruz and outmaneuvered by Cruz in the competition for delegates in Colorado.

As the Trump campaign attempts to get a better handle on the complicated delegate selection process, Trump is expected to send a contingent to a Republican National Committee (RNC) meeting in Florida next week.

Trump has been in a war of words with the RNC, accusing the party apparatus of having rules that, for example, allowed party regulars in Colorado to select delegates without giving Republicans there a chance to vote.

Trump on Tuesday said that RNC Chairman Reince Priebus "should be ashamed of himself."

Priebus, who met Trump two weeks ago at RNC headquarters in Washington, said the delegate-selection rules have been in place for a year and it is the responsibility of each campaign to understand them.

"Complaints now? Give us all a break," Priebus tweeted.