"...Vice President Joe Biden, in a bid to become an influential second-in-command, is striving to carve out meaty roles for himself quickly...Before taking office, Mr. Biden pointedly disavowed the enlarged role of Dick Cheney, whom he called "one of the most dangerous vice presidents" in American history. Some Democratic operatives speculated that his remarks diminished the vice presidency...Obama officials play down Mr. Biden's missteps."..."