Many elections have been altered by an "October surprise," or a sudden revelation that casts one candidate in a bad light. Here are some of the more memorable October surprises from years past:

1816: James Monroe (Democratic-Republican) vs. Rufus King (Federalist)—The Daily Pottstown Ledger intercepts a carrier pigeon carrying erotic poetry from Sen. King to an unidentified minor

1840:William Henry Harrison (Whig) vs. Martin Van Buren (Democrat)—In one of the earliest photographs ever taken in the United States, the incumbent Van Buren is revealed to be nothing more than a topcoat stuffed with leaves

1868:Ulysses S. Grant (Republican) vs. Horatio Seymour (Democrat)—Scandal erupts when it is discovered that Seymour secretly supports polio

1924: Calvin Coolidge (Republican) vs. John W. Davis (Democrat)—Publishing magnate William Randolph Hearst releases photos of Davis dressed as a flapper

1960:John F. Kennedy (Democrat) vs. Richard Nixon (Republican)—Chicago's powerful League of Deceased Voters rescinds its endorsement of Nixon

1984:Ronald Reagan (Republican) vs. Walter Mondale (Democrat)—Ronald Reagan finds Osama bin Laden and gives him $100 million to fight the Soviet occupation of Afghanistan

1988: George H. W. Bush (Republican) vs. Michael Dukakis (Democrat)—Voters are shocked when it is revealed that Dukakis previously slept with and impregnated his wife of many years