The AARP, the nation's largest and most influential association of older Americans, endorsed the House healthcare bill Thursday morning and vowed to lobby House members in advance of Saturday's historic vote. AARP Vice President Nancy A. LeaMond said the House package, which would spend more than $1 trillion over the next decade to expand insurance coverage to millions of Americans who lack it, meets the group's chief goals for reform, including strengthening Medicare. LeaMond praised House leaders for including a plan to close the coverage gap in Medicare prescription drug coverage known as the donut hole.