Trump shifts to new campaign phase, dismisses GOP critics

INDIANAPOLIS (AP) — Donald Trump, the GOP presidential nomination virtually in hand, is signaling a new phase of his outsider campaign, searching for a running mate who could help him govern and reaching out to one-time competitors in an effort to heal the fractured Republican Party.

The former secretary of state suffered a defeat Tuesday in Indiana to her rival, Bernie Sanders, but holds a definitive lead in Democratic delegates who will decide the Democratic nomination.

Hours before clinching victory in Indiana, Trump was floating an unsubstantiated claim that Cruz's father appeared in a 1963 photograph with John F. Kennedy's assassin, Lee Harvey Oswald — citing a report first published by the National Enquirer.

Trump defended his reference to the Enquirer article on Wednesday morning as "Not such a bad thing," but the line of attack was the final straw for some Republican critics.

"(T)he GOP is going to nominate for President a guy who reads the National Enquirer and thinks it's on the level," Mark Salter, a top campaign aide to 2008 Republican nominee John McCain, wrote on Twitter on Tuesday.

While Clinton heads into the general election with significant advantages with minority voters and women, Democrats have vowed to not underestimate Trump as his Republican rivals did for too long.

Only about half of Indiana's Republican primary voters said they were excited or optimistic about any of their remaining candidates becoming president, according to exit polling conducted by Edison Research for The Associated Press and television networks.