WASHINGTON (AP) Sixteen Democrats whove opposed Nancy Pelosis quest to become speaker released a letter Monday saying they will vote for new leadership when the House picks its leaders in January, underscoring a significant threat to her effort to lead her partys House majority in the next Congress.The letters release suggests that rather than spending the next six weeks focusing on a fresh agenda to present to Americans, House Democrats could be consumed with a bitter and attention-grabbing internal leadership fight.