Sanders is the favorite of 41 percent of Democratic voters in the NBC News/Marist poll out Sunday morning, compared to 32 percent for Clinton. Vice President Biden has 16 percent support in the Granite State.
Clinton topped Sanders in New Hampshire, 42 percent to 32 percent, in a similar poll in July.
No other Democratic candidate received more than 1 percent support in the latest sampling.
Another NBC/Marist Poll out Sunday found that Sanders is gaining ground on Clinton in Iowa, where her lead over the Vermont senator has shrunk 13 points since July.
She now takes 38 percent support in Iowa, compared to Sanders’s 27 percent.
On the Republican side, front-runner Donald Trump has a 7-point lead in Iowa and tops the GOP field by 16 points in New Hampshire.
Ben Carson holds the second spot in Iowa, while Ohio Gov. John Kasich is in second place in New Hampshire.
The Iowa poll, conducted Aug. 26-Sept. 2, has a 3.1 percent margin of error for registered voters, a 5.0 percent margin of error for potential GOP caucus-goers and a 5.3 percent margin of error for potential Democratic caucus-goers.
The poll in New Hampshire, conducted Aug. 26-Sept. 2, has a 3.2 percent margin of error for registered voters, a 4.8 percent margin of error for potential GOP primary voters and a 5.2 percent margin of error for Democratic primary voters.
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