Supporters of Democratic 2020 U.S. presidential candidate and former Vice President Joe Biden listen a televised message from South Carolina at his New Hampshire primary night rally in Nashua, New Hampshire U.S., February 11, 2020.

Democratic U.S. presidential candidate Senator Bernie Sanders is accompanied by his wife Jane O’Meara Sanders and other relatives as he arrives to speak at his New Hampshire primary night rally in Manchester, N.H., U.S., February 11, 2020.

Democratic U.S. presidential candidate Senator Amy Klobuchar speaks at her New Hampshire primary night rally in Concord, N.H., U.S., February 11, 2020.

Democratic U.S. presidential candidate Senator Amy Klobuchar speaks at her New Hampshire primary night rally in Concord, N.H., U.S., February 11, 2020.

Democratic U.S. presidential candidate and former Vice President Joe Biden speaks to supporters at a campaign rally on the night of the New Hampshire primary in Columbia, South Carolina, U.S., February 11, 2020.

Democratic U.S. presidential candidate and former South Bend Mayor Pete Buttigieg speaks at his New Hampshire primary night rally in Nashua, N.H., U.S., February 11, 2020.

Democratic 2020 U.S. presidential candidate and former Vice President Joe Biden accompanied by his wife Jill speaks to supporters on televised message from South Carolina at his New Hampshire primary night rally in Nashua, New Hampshire U.S., February 11, 2020.

Democratic U.S. presidential candidate Senator Elizabeth Warren speaks at her New Hampshire primary night rally in Manchester, New Hampshire, U.S., February 11, 2020.

Democratic U.S. presidential candidate Senator Elizabeth Warren embraces a supporter at her New Hampshire primary night rally in Manchester, New Hampshire., U.S., February 11, 2020.

Democratic U.S. presidential candidate Senator Elizabeth Warren speaks at her New Hampshire primary night rally in Manchester, New Hampshire, U.S., February 11, 2020.

U.S. Democratic presidential candidate Senator Amy Klobuchar greets supporters at her New Hampshire primary night rally in Concord, New Hampshire, U.S. February 11, 2020.

US Democratic presidential candidate and former Vice President Joe Biden appears at a New Hampshire primary night campaign rally in Columbia, South Carolina, U.S., February 11, 2020.

Democratic U.S. presidential candidate and former Vice President Joe Biden speaks to supporters at a campaign rally on the night of the New Hampshire primary in Columbia, South Carolina, U.S., February 11, 2020.

Democratic U.S. presidential candidate Senator Bernie Sanders addresses supporters at his New Hampshire primary night rally in Manchester, N.H., U.S., February 11, 2020.

Democratic U.S. presidential candidate Senator Bernie Sanders speaks at his New Hampshire primary night rally in Manchester, N.H., U.S., February 11, 2020.

Democratic U.S. presidential candidate and former South Bend Mayor Pete Buttigieg waves to the crowd with his husband Chasten at his New Hampshire primary night rally in Nashua, N.H., U.S., February 11, 2020.

Democratic U.S. presidential candidate and former South Bend Mayor Pete Buttigieg with his mother Jennifer Anne Montgomery and husband Chasten at his New Hampshire primary night rally in Nashua, N.H., U.S., February 11, 2020.

Democratic U.S. presidential candidate Senator Bernie Sanders is accompanied by his wife Jane O’Meara Sanders and other relatives as he speaks at his New Hampshire primary night rally in Manchester, N.H., U.S., February 11, 2020.

Supporters cheer as Democratic U.S. presidential candidate Senator Bernie Sanders speaks at his New Hampshire primary night rally in Manchester, N.H., U.S., February 11, 2020.