Democratic presidential contender Michael Dukakis held a 15-point lead over Republican George Bush in an NBC News-Wall Street Journal poll released Thursday, largely on the strength of overwhelming support for Dukakis among women. Dukakis was supported by 49 percent of the registered voters in the poll, to 34 percent for Bush, NBC News reported. Among men the split was 46-40 for Dukakis, but among women his margin was 52-28.