Former Massachusetts Governor Mitt Romney headlined congressional Republicans' big new policy conclave over the weekend, stressing the need to listen to real Americans, but also appearing to slap a potential rival for the 2012 GOP presidential nomination. At the National Council for a New America's first "conversation" in Arlington, Va., Romney, who ran for the Republican nomination last year and has kept his name in the conversation for 2012, joined House Republican Whip Eric Cantor and former Florida Governor Jeb Bush in presiding over the panel. "I’ve learned that when you sit in a position of responsibility as you do...