Bernie Sanders has reached his highest level of support this year in the latest NBC News/SurveyMonkey online poll.
He is now the preferred candidate of 33 percent of Democratic and independent voters who lean Democratic. However, he still trails Hillary Clinton by 16 points, and his slight gain of 3 points since last month's poll is barely perceptible and within the poll's error estimate of plus or minus 3.1 percentage points.
Martin O'Malley has struggled to make any kind of impact on Democratic voters, despite now having been on a national debate stage twice with his rivals.
The latest NBC News/SurveyMonkey online poll was conducted Sunday through Tuesday among 5,755 adults nationwide, including 1,983 Democratic voters and independent voters who lean Democratic. Overall results have an error estimate of plus or minus 1.9 percentage points and the error estimate for the leaned Democratic voters is plus or minus 3.1 percentage points.