From the Washington Examiner:
The latest NBC News/SurveyMonkey weekly online tracking poll says Clinton is just barely ahead of Sanders, 49-43, among Democratic and Democratic-leaning voters. Those numbers came out just after Sanders chalked up wins in Washington, Alaska and Hawaii.
Just last week, Clinton was ahead by 21 points, 52-31. Since the beginning of March, Clinton has dropped by a total of six points, while Sanders has gained five.