Sen. Bernie Sanders, I-Vermont, now has a significant lead over Hillary Clinton in New Hampshire, which will hold the first-in-the-nation primary on Feb. 9., according to a new survey.

A CNN/WMUR poll released Tuesday found Sanders is now 27 percentage points ahead of Clinton, leading her 60 percent to 33 percent. Sanders' support in New Hampshire has increased 10 percentage points since the last poll was conducted in late November and early December.

The latest poll also found than 52 percent of New Hampshire Democrats are now sure about their choice for president, up from 36 percent who felt that way in early December.

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Seventy percent of New Hampshire's undeclared voters -- those not registered in either major political party -- said they plan to vote for Sanders while 25 percent of them said the same about Clinton. Among registered Democrats, the poll found Sanders leads Clinton 50 to 41 percent.

It could be Sanders' views on the economy that could be giving him a boost. Fifty-seven percent said Sanders would be the best person to handle the economy while 33 percent said Clinton would do the best job.

Polls last week showed that Sanders is not only leading Clinton in New Hampshire but the race between the two of them is tightening in Iowa, which will hold its caucuses on Feb. 1.

The poll surveyed 927 adults in New Hampshire, with 420 who plan to vote in the Democratic primary, between Jan. 13 and 18, before Sunday's Democratic debate. The margin of error is 4.8 percentage points.