Maria Shriver has left Arnold Schwarzenegger because Arnie had a tryst with one of his housekeepers and fathered a child with her.
I get the impression that the only thing that will make a liberal woman separate from a liberal man is if the liberal man fathers a child with another woman. An example: Elizabeth Edwards. She stuck next to John Edwards no matter how much he betrayed her and slept around. Any kind of dalliances; adultery, child molestation, lying, taking up with a prostitute, etc., is all forgiven by liberal women. But having a kid - that'll make them leave.
Thinking about it, I can see why: liberal women cling to their husbands so they can take advantage of their money and/or fame (think of Hillary Clinton). If their loser husband has a kid with a different woman, that means the loser husband has to pay child support to another woman, which means there's less money for the liberal wife. She can't have that.
It's all the same with liberals: How much money they can suck out of the system. When the quantity of cash goes down, they move on to greener pastures.