Ciccina asks a question over at Pollster.com:
"[quoting Bill Schneider of CNN]"...it looks like the gender gap, long a feature of politics between Democrats and Republicans, has established itself in the Democratic primaries."
....So what is Bill on about? Did something different actually happen, or is he just resorting to the "b-list" material since there isn't much data by race to talk about?"
That got me thinking, and so I spent some time looking up the exit poll data provided by MSNBC (CNN for Wisconsin - for some weird reason MSNBC does not report WI data!)
First, here's the difference between the fraction of women and fraction of men for Senators Clinton and Obama (note: this is not the gender gap referenced by Ciccina/Bill Schneider!):

It looks like Senator Clinton wins as much more women than men, as Senator Obama does more men than women. Since women outnumber men among Democratic voters (the average male/female split in these Democratic primaries/some caucuses is 42.5/57.5), this could give Senator Clinton an advantage... Except that it looks like the "popular vote" is a wash (Senator Obama leads by a few hundred thousand out of ~30 million cast in primaries.)
[Of course, the "popular vote" race is fatally flawed: see this dkos post.]
So let's examine the data more carefully. I consider only primaries - no caucus estimates. I also do not count Florida and Michigan.
My popular-vote data haven't been updated particularly for earlier contests after provisional ballots have been counted. But it appears that - out of 30.4 million voters that I account for - Senator Clinton has won women 51.8-45.5 (+6.3%), while Senator Obama wins men 52.7-43.1 (+9.6%). That larger gap among men makes the "popular vote" race effectively a wash.
| Primaries | Women | Women (%) | Men | Men (%) | Women/Total |
| Clinton | 9052336 | 51.8% | 5562068 | 43.1% | 61.9% |
| Obama | 7952867 | 45.5% | 6794579 | 52.7% | 53.9% |
[As my popular vote data are just two-candidate totals - excluding most prominently John Edwards' votes - there are some errors particularly early on. But overall, this should be a minor error.]
On to the gender gap. My definition is: Clinton(females - males) - Obama(females - males).

First, women usually make more than half of either candidate's votes - this is to be expected in a Democratic race, as women make up 58% of the electorate. The exceptions are Senator Obama's voters in CA, RI and WV.
Second, the gender gap (as I define it) is almost 30% in WV - after being less than 10% in IN and NC, and 20% in PA. I suppose that's what Bill Schneider meant - the gender gap had almost disappeared in the past few weeks, post-PA and pre-WV.
Spin: Men vote for the man in the race, so they are sexist. Or - women are preferentially voting for the weaker candidate, so they are standing by a sister!