About 25% of all Americans are descended from from the orginal Mayflower settlers of Plymouth Colony.
FDR and George W. Bush are both directly descended from John Cooke and his father Francis Cooke.
George W. Bush is descended from the British Royal family on his father's side and from the Mayflower Spencers (Princess Di) on his mother's side - making President Bush related on both sides to both parents of the current Princes of England.
FDR was a cousin of his wife Eleanor Roosevelt - who was related to Teddy Roosevelt.
John Forbes Kerry (Kohn) is a cousin of President George W. Bush but was so smart in 2004 he chose to hire an idiot who traced his roots back to French royalty.
Franklin Delano Roosevelt is related to at least 8 other American Presidents and 3 other Mayflower families.
Other relatives include Humphrey Bogart, Marilyn Monroe, Clan MacLeod, Dan Quayle, Richard Nixon, Samuel Colt, William Cody, John Alden, Priscilla Mullins, James Roosevelt, Sara Delano, Clara Barton, Susan B. Anthony, Tennessee Williams, Robert Goddard, Eleanor (Yikes!) Clift, James Alfred Van Allen,
Calvin Coolidge, Lincoln D. Chafee, George Washington, Thomas Jefferson, Robert E. Lee; - the genwebsite database covers well over 80,000 people.