WASHINGTON--In keeping with a longstanding Thanksgiving tradition, Vice President Joe Biden ceremonially pardoned a 4-pound yam today at a ceremony in the White House Rose Garden. "Under my authority as vice president of the United States of America, I hereby grant this yam full and unconditional clemency," a smiling Biden declared as he gently patted "Spud," a Beauregard sweet potato grown in Louisiana and selected from millions of candidates yielded by this year's harvest. "May he never find himself in a casserole. Right, little guy?"