The Trans-Pacific Partnership (TPP) (see also this view of the TPP, among others) would become FEDERAL law, not STATE law, so you should start your research with your Oregon Congressional Delegation. This is not to say you shouldn’t also talk to your Oregon state representatives, who should be conversant on the subject of the TPP anyway, if only because any national trade laws will affect you locally, your business, you as consumer, and all of us (most of us) as taxpayers.
A brief tutorial:
Full text version of the TPP, from the Office of the United States Trade Representative
You can find more, much more, commentary and summaries on the TPP from numerous organizations, political, advocacy, fair trade, free trade, unions, corporations, PACs, and many more.
Do your research, read all sides, talk to your federal legislators and their staff members, and vote if you want to be counted. (Note: being “counted” doesn’t mean you win. It means you get to play the game with your teammates and the other side’s teammates instead of sitting on the bench and whining.)