A lot of blogs have been weighing in on this issue lately, and BuyBlue.org is a good resource if you're looking for a simple breakdown of which party some major companies sent their political lucre out in search of returns. It's a pretty simplistic way to look at it, which means it's got some potential (or real--I haven't done the research yet) flaws.
There are some no-brainers--I'm joining Costco this year, but for more than their political stance. I like the way they do business. I like the fact that their CEO gives stock analysts the fat middle finger when they suggest that he's fucking over stockholders by not treating his employees like serfs. I like the fact that he doesn't want a high employee turnover rate, even if it means his employees get a gasp! raise from time to time. I like that he's not union hostile. So I'd be joining Costco even if they didn't give the vast majority of their political contributions to the Democratic party.
Wal-Mart is another no-brainer. For the opposite of every reason I noted why I will go to Costco, I will never go into another Wal-Mart, even if they give Democrats huge campaign contributions, not unless they change their filthy business practices. They could personally finance the campaign of every single Democrat in 2006 and I wouldn't go in there unless they start treating their employees like they're more valuable than used disposable diapers.
I'll admit--in a pinch, looking at where a company puts its political capital is better than nothing, but it's hardly the entire answer. And I'm not asking for a boycott of any company that doesn't show overwhelming loyalty to the Democratic Party. Hell, I'd be satisfied if they split their donations equally, or even better, if they got out of the political donation game altogether. In fact, I'll swear undying loyalty to any company who does just that--stays the hell out of politics and leaves it to the individual citizens. Deal?