A recent Gallup poll (Feb 1-9) of likely Democratic voters finds a gender gap among White and Hispanic voters but not with Black voters. The bottom line:

White Men: Clinton 50% — Obama 40%
White Women: Clinton 59% — Obama 31%

Hispanic Men: Clinton 56% — Obama 39%
Hispanic Women: Clinton 65% — Obama 28%

Black Men: Clinton 25% — Obama 69%
Black Women: Clinton 23% — Obama 66%