MANCHESTER, NH (AP) - Mitt Romney eagerly pocketed an endorsement from two-time New Hampshire primary winner John McCain on Wednesday and bid to convert a single-digit victory in Iowa into a Republican presidential campaign juggernaut. Unimpressed, Newt Gingrich ridiculed the former Massachusetts governor as a liberal turned moderate now masquerading as a conservative.Former Pennsylvania Sen. Rick Santorum sought to rally conservatives to his side after coming achingly close to victory in Iowa, saying he "hoped to surprise a few people just like we did" in the campaign's first contest."This is a wide-open race still," added former Utah Gov. Jon Huntsman, …