Goldman Political Contributions

Here is the news article I was referring to in our discussion in class yesterday about whether or not corporations should contribute to political campaigns:

http://www.usatoday.com/news/politics/2010-04-20-goldman-sachs-donations_N.htm

To me it certainly seems like there is a strong correlation between the amount of money Goldman Sachs has contributed- especially to people in Finance overseeing positions and the fact that the specific case the SEC is bringing up against Goldman Sachs is not necessarily an easy case to win. The SEC could have gone a different route and gotten them in trouble for unethical behavior but instead they have chosen to sue them for something which leaves them room to potentially escape unscathed. What is the motivation of the SEC for doing this? In my opinion: $$$.