WASHINGTON (Reuters) - Campaign advisers to President Barack Obama promised on Sunday he would be more aggressive and energetic on Tuesday in his second debate against Republican challenger Mitt Romney after a passive, heavily criticized performance in their first showdown. Since that first debate in Denver on October 3, polls indicate Romney has erased Obama's lead heading into the November 6 election. Obama and Romney debate again on Tuesday at Hofstra University in Hempstead, New York. The third and final presidential debate will take place on October 22 in Florida. ...