Being left out is bad news for agricultural and industrial states such as Illinois — heavy exporters that sell corn, soybeans, pork, machinery and plenty of other products around the world. The point of TPP is the same as other agreements, such as NAFTA: to break down trade barriers and encourage interdependence in ways that help all sides, buyers and sellers.TPP would have slashed high taxes on U.S. exports to member countries and helped small and midsized American businesses by reducing paperwork burdens. With the U.S. on the outside looking in, those other countries are more likely to trade among themselves.