This post will be largely a collection of links.
Senator Clinton has lately been suggesting that sexism is keeping her from winning the Democratic nomination, e.g. hear this WaPo interview.
Before this interview, Marie Cocco wrote about misogyny this primary season.
Megan McArdle @ The Atlantic writes about the "privilege olympics" between sexism and racism (and comes down on the side of sexism). McArdle and Daniel Drezner talk about sexism hurting Senator Clinton as well as about women in leadership positions (I think the latter was more informative).
Here's Ciccina on sexism and misogyny (includes a link to an interesting study that shows a female version of the Bradley effect.)
Chris Mathews' Hardball takes on the sexism issue:
[I shall keep updating with interesting articles I find. I have written earlier about sexism and racism here (I rant about Obama supporters being called sexist) and a little bit here (looking at a recent Quinnipac poll; the comments section has a more interesting discussion with Ciccina).]