Mitt Romney announced Friday he will not run for president in 2016, after briefly flirting with a third White House run -- a decision that only slightly narrows the crowded field of potential Republican candidates. "After putting considerable thought into making another run for president, I've decided it's best to give other leaders in the party the opportunity to become our next nominee," Romney told donors on a conference call Friday morning. The announcement comes after the 2012 GOP nominee, who repeatedly denied interest in another campaign, surprised donors earlier this month by telling them he was considering it. Since...