Candidates Campaign Before Super Tuesday

Supporters look on as democratic presidential candidate former Secretary of State Hillary Clinton speaks during a "Get Out The Vote" event at the Old South Meeting Hall in Boston, Massachusetts, Feb. 29, 2016.

Democratic presidential candidate former Secretary of State Hillary Clinton speaks during a "Get Out The Vote" event at the Old South Meeting Hall in Boston, Massachusetts, Feb. 29, 2016.

Republican presidential candidate, Donald Trump waves to the crowd during a rally at Radford University in Radford, Virginia, Feb. 29, 2016.

Guests listen to the national anthem during a campaign rally for Republican presidential candidate Donald Trump at the Madison City Schools Stadium in Madison, Alabama, Feb. 28, 2016.

Supporters hold signs for Republican presidential candidate Marco Rubio during a campaign rally at the Intercontinental Buckhead Hotel in Atlanta, Georgia, Feb. 29, 2016.

Republican presidential candidate Marco Rubio holds a campaign rally at the Intercontinental Buckhead Hotel in Atlanta, Georgia, Feb. 29, 2016.

Supporters of Democratic presidential candidate Sen. Bernie Sanders (D-VT) hold sings in support during his speech at the Minneapolis Convention Center in Minneapolis, Minnesota, Feb. 29, 2016.

Democratic presidential candidate Sen. Bernie Sanders (D-VT) speaks to a crowd of supporters at the Minneapolis Convention Center in Minneapolis, Minnesota, Feb. 29, 2016.

U.S. Republican presidential hopeful Sen. Ted Cruz speaks to the media with Texas Governor Greg Abbott and former governor Rick Perry following a campaign rally in Dallas, Texas, Feb. 29, 2016

People attend a rally by Republican presidential candidate Sen. Ted Cruz (R-TX) at Gilley's Dallas the day before Super Tuesday in Dallas, Texas, Feb. 29, 2016.

Ohio Governor and Republican presidential candidate John Kasich speaks at an event at Plymouth Memorial Hall in Plymouth, Massachusetts, Feb. 29, 2016.

Republican presidential candidate retired neurosurgeon Ben Carson speaks at the National Religious Broadcasters convention in Nashville, Tennessee, Feb. 26, 2016.