The parcel supposedly contains something that would "bring the senator's plan to public". If he is truly simply planning to speak his mind while "upholding what the Republic stands for", why hide it? What kind of democracy lies in secrecy?
Getting darkside points for trying to reveal some evil senator's plans to betray the republic is mindboggling.
Personaly I think this quest was put in just to show how confusing the political situation is there, but it failed. Its painfuly obvious that the senator is the "bad guy". The person who stops you doesn't even argue on that point. Merely that I am interfering with the political process and some gibberish about not letting him have his own view or soemthing. When all my character was doing is letting everyone else know what his hidden view/plan/whatever was.
If the negative points were because of the method of doing it, then you should get just as many darkside points for lying to and decieving the person you are supose to be working for. A MUCH better way to express the confusion and corruption is if the documents had turned out holding some other sort of sensitive information, and you wound up destroying a senators career that was loyal to the republic.
In the long run. I don't think that one light/dark choice will make that much difference though.