The former president calls his son "the right man for the challenges ahead."
Bush said troops who lost their lives for Bergdahl "didn't get the same attention."
Jim Talent served on the Senate Armed Services Committee before losing in 2006.
Eric Holcomb is a former Indiana GOP chairman.
The GOP dissenters included hard-line conservatives and centrists.
Former Sen. Kay Bailey Hutchison is endorsing Jeb Bush for president.
Ron Johnson, a top Democratic target, says student loans are too easy to get.
Leadership Matters for America hired Upstream Communications to manage online strategies.
The governor called for a candidate "who wants to do something, not just be somebody."