The single female voters are already deep in his corner. This is old news. There is no way that bloc of voters would vote for McCain, or for that matter any Republican...or RINO.
Think for a sec who most of those folks are. Think about their education, what they watch in the media, who their heros are, and who has influnced their lives. There are more factors...those are just a smidge...but suffice to say, most are hardcore Dems...who likely would have voted for the HillDog...but now will gladly accept Door Number 2 rather than vote like a conservative male.