First, it is false. Polls put Obama over Romney among female voters by 8, 10, or 16 points, according to the first three results I found in Google News. Moreover, in 2008 Obama won the female and tied the male vote, while now he seems to be winning the female vote by a somewhat smaller amount, but losing substantially the male vote. So looking at the female/male ratio (to control for the state of the economy and other general features) it looks as of now that Romney does worse with women than McCain did.

Of course, not every false statement about women is sexist. But I would say that an analysis attributing (in a false and unsubstantiated way) women's voting choices to irrational, subconscious factors as opposed to conscious ideological preference or self-interest, while not making a similar analysis for men's voting choices, is sexist.

Also, in my opinion it edges into outright misogyny because the paragraph

Professor Obama? Two daughters. May as well give the guy a cardigan. And fallopian tubes.

is not merely an objective analysis that in the author's opinion women will see Obama as weak/emasculated//whatever for having daughters instead of sons: it actively mocks Obama and expresses contempt for him on that basis, thus reinforcing the idea that women are less valuable than men.