Sen. John McCain (R., Ariz.), who faces his own primary challenge from the right, says yes:
Sen. John McCain on Sunday joined a cast of former presidential candidates and high-ranking Republicans to weigh in on Florida’s August GOP senatorial primary between Florida Gov. Charlie Crist and former Florida House Speaker Marco Rubio.
“I hope that Charlie Crist will remain a Republican,” McCain said.
. . . Crist threw his support to McCain in Florida’s 2008 presidential primary. McCain won the primary and Rudy Giuliani dropped out of the presidential race the next day.
Here’s Rich’s take:
Switching parties because he fears losing a primary, a primary he said he was committed to seeing through to the end, would only make Crist’s chief vulnerability worse. No one — conservative, liberal, or in between — likes an opportunist, and Crist would have established himself as one beyond any argument. He’d be Arlen Specter, except without a party.
McCain, for his part, now leads former GOP congressman J.D. Hayworth by five points, 47 percent to 42 percent, according to a Rasmussen poll released on Friday.