Doing some calculations of my own, here are Obama's margins of improvement based on 2004 and 2008 exit polls:

White Women: +4
White Men: +9

Now let's multiply this by the percentage of the 2008 electorate, to see how each group affected Obama's topline margin in the popular vote compared to 2004:

White Women: +1.84 points
White Men: +3.69 points

As you can see, among whites the 2008 Democratic margin increased twice as much due to men as due to women.

As another example, let's take the much hyped youth vote of ages 18-29.

Patrick Ruffini already did the math for us, and the youth vote swing was worth an impressive +4.5 points for Obama.

To reiterate: "White Men" and "Youth of all races and sexes, age 18-29" are both at least twice as more significant than "White Women" in raising Obama's numbers.

Don't get me wrong, it's lovely for women that they vote more Democratic than men and are a greater percentage of the electorate, but they barely moved from 2004, and moved less than half of the national trend. In order to be a factor in "sealing the deal", a group has to improve significantly, and white women barely moved (+4 compared to white men's +9 shift, and Obama's +9 among the electorate as a whole)

My numbers are the swing because that's what matters for an apples to apples comparison.

Point is they didn't seal any deal because they underperformed behind Obama's numbers elsewhere.

All you can get from Ruth's analysis is that Democrats depend on doing better with women to win, just like Republicans depend on doing better with men. We already knew that, and it's irrelevant to "deal sealing".

Women always make up a significant proportion of the electorate for any Democrat, certainly, but in this election Obama actually underperformed with women compared to the majority of other demographic groups.

Kevin Drum explains it here. Women did not seal the deal. Sorry.

Those who did:

Income $200,000 or more (+34)
First-time voters (+33)
No high school (+27)
Latinos (+27)
18-29 year olds (+25)
Under $15,000 (+21)
Full-time workers (+19)
Urban (+19)
Non-gun owners (+18)
Non-religious (+16)
Parents with children under 18 (+16)

Those who didn't:

Gay/lesbian (-11)
Last minute voters (-8)
Union members (0)
"Other" religions (0)
Gun owners (+2)
White women (+4)
45-59 year olds (+4)