What's a good "liberal" to do?

Apparently some "liberals" are boycotting Amazon because their employees donate to Republicans in a 60-40 ratio over Democrats.

Per Pandagon:

I'll certainly buy more from Barnes and Nobles (91% Democrat) and Borders (100% Democrat), but I don't know that giving up Amazon is the right thing to do...

Apparently they didn't get the memo. B&N and Borders are evil! Shouldn't "liberals" only patronize local bookshop collectives?