If you ever need some free tools to lookup politicians and see who's backing them financially, try out these sites.
They each give a different search method for looking up contributors and who they are supporting. Politicalbase, is the most recent website and does a majority of the things you need to "Follow the money".
For instance, if you go here: www.politicalbase.com/money/ and type Google in company field you'll notice that they lean very strongly to the Democrats and if you search for "exxon" you get more towards the Republican side so you get the idea.
More interestingly, if you Search for "David Drummond" (an Executive at Google), you will see he made a $1000 contributions to a Republican Senator in Alaska, Ted Stevens. This is not only odd because Mr. Drummond is clearly a Democrat, but if you Google "Ted Stevens", you will find that he is notoriously known for calling the internet "a series of tubes" . Very funny indeed, Mr. Drummond, but it must be nice to be able to donate $1000 to a politician simply as a practical joke.
David Drummond, you're my new hero, and my paypal address is: bradoyler AT gmail com. So feel free to paypal me $1000 anytime, I'll call the internet whatever the hell you want!