Democrats lean heavily on young voters to win elections, but their leading candidates for the White House are 68-year-old Hillary Clinton and 74-year-old Sen. Bernie Sanders (I-Vt.). The two other Democrats who were often implored to enter the race are Vice President Biden, 72, and Sen. Elizabeth Warren (D-Mass.), 66. Democrats are led on Capitol Hill by House Minority Leader Nancy Pelosi (Calif.) and Senate Minority Leader Harry Reid (Nev.) - who are both 75. Pelosi's top two lieutenants are 76-year-old Minority Whip Steny Hoyer (Md.) and 75-year-old Rep. James Clyburn (S.C.). In comparison, Reid's expected successor as Democratic leader...