Former President George H.W. Bush says his son Jeb should run for president in 2016.
McCain said he is "very pleased" his "friend" Clinton can join this year’s forum.
A Quinnipiac poll shows the Ky. Republican would lead the Dem front-runner by 5 points.
The Republican Conference chairman was also seen as a likely candidate in 2012.
One of them came during the 2000 presidential race and involved the Confederate flag.
Dole had argued that Paul and others lack the experience to run for president.
Former Sen. Bob Dole said Cruz was an "extreme right-wing guy."
Simon & Schuster is publishing the book, set for release on June 10.
The former first daughter, 34, made the big reveal in New York City.
New Jersey Gov. Chris Christie (R) on Thursday welcomed Vice President Biden to Instagram with an old photo of them together.