A new Fox News national poll released Monday evening found that support for Hillary Clinton among likely Democratic primary voters has slipped below 50 percent, giving Clinton her smallest lead over Bernie Sanders yet.

Clinton received 49 percent of the vote, just 12 percent more than the Vermont senator's 37 percent. Two weeks ago, the former secretary of state's lead was 15 points higher than Sanders, and she led 55-39 percent. Former Gov. Martin O'Malley got 1 percent of support from those polled from Jan. 18 to Jan. 21.

Since June, Clinton has lost almost three-quarters of her 46-point lead over Sanders. Other Fox polls indicate Sanders may be appealing to African-American voters, whose support for Clinton has shrunk since December's 84 percent to a current 67 percent.

Clinton's supporters were also more accepting of a Sanders nomination than his were of Clinton's winning the selection.

Twenty-seven percent of Sanders' backers would be satisfied if Clinton won, while 52 percent said they would be dissatisfied with the party's choice, but still vote Democratic in the election.

In contrast, 43 percent of Clinton supporters would be satisfied with a Sanders nomination and 33 percent said they wouldn't be happy, but would still support him in the general election.