WASHINGTON (AP) — Indiana Gov. Mitch Daniels has endorsed presumptive Republican presidential nominee Mitt Romney.Daniels, once thought to be considering a presidential run of his own, says he'll do whatever he's asked to help the former Massachusetts governor defeat President Barack Obama. The Romney campaign announced the endorsement Wednesday morning.Daniels consistently declined to endorse Romney before his lock on the GOP nomination was secure. He's also mentioned as a possible choice for vice president.The Romney campaign initiated that search this week.Prior to serving as Indiana governor, Daniels served as director of the Office of Management and Budget in President George W. Bush's administration. He's also a former advisor to President Ronald Reagan.