A new poll of likely Democratic primary voters in New Hampshire finds Vermont senator Bernie Sanders with a 14-point lead over Hillary Clinton, the former secretary of state. Sanders, a self-proclaimed socialist, has 53 percent support according to the new poll from Monmouth University. Clinton, meanwhile, has just 39 percent support.

That's a big shift from Monmouth's November poll, which found Clinton had 48 percent to Sanders's 45 percent. And as the February 10 primary approaches, more Democrats than ever before—52 percent—say they are "completely decided" on who they will support. That's more the case with Sanders supporters than Clinton ones. Sanders and Clinton also have a nearly equal percentage of Democrats who say they could support them—20 percent for Sanders, 21 percent for Clinton.

According to the Real Clear Politics average of polls for New Hampshire, Sanders has a more modest 4.3-point lead over Clinton, though that average does not include the new Monmouth poll. In Iowa, things are slightly better for Clinton ahead of the February 1 caucus—she's got a 5.8 lead over Sanders. But the trend is in the wrong direction for the former First Lady, with Sanders appearing to gain on Clinton in recent polls.