For the second year in a row, Mormon President Thomas S. Monson stands atop the list. As the divine prophet, seer, and revelator for 5.5 million Americans and more than 12 million people around the world, he's the most powerful 83-year-old we could find. Look for Monson to stay on top for years to come—at least until Boyd K. Packer, octogenarian president of the Quorum of the Twelve Apostles, succeeds him as the alpha Mormon.
First runner-up is the senior senator from Hawaii, Daniel Inouye. When West Virginia's Robert Byrd moved into our "Just Missed" section in June, the 86-year-old Inouye was sworn in as president pro tempore of the Senate—which puts him just three heartbeats away from the Oval Office. He's also the chairman of the appropriations committee—and responsible for about $400 million in earmark spending in 2010.
See the other 78 powerful octogenarians at the post. Link