LAS VEGAS — Vice President Joe Biden denounced Republican presidential challenger Mitt Romney on Tuesday as a candidate with something to hide. Biden, campaigning for President Barack Obama in the battleground of Nevada, told Hispanic leaders that Romney doesn't live up to the openness that his father represented when he ran for president 44 years ago. The vice president said Romney's father, George Romney, released 12 years of tax returns when he unsuccessfully sought the Republican nomination in 1968. In excerpts of Biden's remarks released by the Obama campaign, Biden told the annual conference of the national Council of La...