Mitt Romney secured a close victory in Ohio but failed to land a knockout blow against rival Rick Santorum on "Super Tuesday," raising the odds of a drawn-out battle for the Republican presidential nomination between the party's establishment and its grassroots conservatives. Romney won five of the 10 state contests on Tuesday but his margin of victory was uncomfortably slim in Ohio, the night's biggest prize. Ohio is a politically divided state sure to be hotly contested in the November 6 election between the eventual Republican nominee and President Barack Obama. Romney moved closer to the 1,144 delegates needed to...