The fate of delegates pledged to former candidates differs from state-to-state, depending on party rules.
In Michigan, delegates are free to vote for whomever they like, according to University of Kansas political science professor, Burdett Loomis. In Massachusetts, delegates pledged to former Gov. Mitt Romney are supposed to follow his lead.
But delegates can vote as they see fit; "In the end, most delegates are free agents. There's no real sanctions against any delegate who changes his of her mind."
So while Romney can encourage his delegates to support McCain, they are not bound to do it. "You can imagine some conservatives who signed on for Romney having a big problem with being asked to support McCain," Loomis says.
— Nancy Cook
Former presidential candidate Mitt Romney has endorsed his presidential rival and has urged his pledged delegates to throw their support to Arizona Sen. John McCain.
"I am honored today to give my full support," Romney said from his now-defunct campaign's headquarters in Boston. "I'm asking my delegates to vote for Senator McCain at the convention."
With the addition of Romney supporters, this puts McCain roughly 70 delegates away from the total number needed to secure the party's nomination.
It also could characterize Romney as a good party member— with the hope this could add him to the shortlist of vice presidential candidates.