Democratic presidential candidate Hillary Clinton stands on the plane to Cedar Rapids, Iowa, with Huma Abedin on Friday, October 28. That day, FBI Director James Comey notified Congress about his bureau's decision to review emails potentially related to Clinton's personal server. JEWEL SAMAD/AFP/Getty Images

Republican presidential nominee Donald Trump arrives at a campaign rally in Springfield, Ohio, on Thursday, October 27. Evan Vucci/AP

Democratic presidential nominee Hillary Clinton campaigns in Winston-Salem, North Carolina, with first lady Michelle Obama on Thursday, October 27. Melina Mara/The Washington Post/Getty Images

The plane that was carrying Indiana Gov. Mike Pence, Donald Trump's running mate, slid off a runway after landing at New York's LaGuardia Airport on Thursday, October 27. No injuries were reported. DON EMMERT/AFP/Getty Images

Khizr Khan, a Gold Star father, campaigns for Hillary Clinton in Norfolk, Virginia, on Wednesday, October 26. Khan made headlines at the Democratic National Convention when he criticized Donald Trump in his speech and held up a copy of the U.S. Constitution. Khan's son, U.S. Army Capt. Humayun Khan, was killed in 2004 while serving in Afghanistan. Julia Rendleman/The Washington Post/Getty Images

Workers repair Donald Trump's star on the Hollywood Walk of Fame after it was vandalized on Wednesday, October 26. David McNew/Getty Images

Democratic presidential nominee Hillary Clinton speaks at a campaign rally in Manchester, New Hampshire, on Monday, October 24. Justin Sullivan/Getty Images

Republican presidential nominee Donald Trump attends a ribbon-cutting ceremony for the Trump International Hotel in Washington on Wednesday, October 26. Joining Trump, from left, are his sons Donald Jr. and Eric; his wife, Melania; and his daughters, Tiffany and Ivanka. Manuel Balce Ceneta/AP

U.S. Rep. Patrick Murphy, left, and U.S. Sen. Marco Rubio have their makeup touched up during a debate break in Davie, Florida, on Wednesday, October 26. Murphy is running for Rubio's Senate seat. Wilfredo Lee/AP

Democratic presidential nominee Hillary Clinton steps off her plane in Charlotte, North Carolina, on Sunday, October 23. Mary Altaffer/AP

While attending a Donald Trump campaign rally, supporter Donna Decker screams at reporters in Tampa, Florida, on Monday, October 24. Evan Vucci/AP

Republican presidential nominee Donald Trump hugs an American flag as he arrives at a campaign rally in Tampa, Florida, on Monday, October 24. Evan Vucci/AP

People cheer for Democratic presidential nominee Hillary Clinton as she speaks at a rally in Tampa, Florida, on Wednesday, October 26. Andrew Harnik/AP

The cable TV channel Animal Planet has memorabilia that plays off the campaign slogans of both Hillary Clinton and Donald Trump. Tom Williams/CQ-Roll Call Group/Getty Images

Indiana Gov. Mike Pence, Donald Trump's running mate, prays with his staff before taking the stage in Marietta, Ohio, on Tuesday, October 25. Spencer Platt/Getty Images

Democratic presidential nominee Hillary Clinton delivers birthday cake to reporters aboard her campaign plane on Wednesday, October 26. She turned 69. Justin Sullivan/Getty Images