sentences:  In "Twin Cities", the Court stated that "[i]t is not for courts ... to substitute their judgments for congressional decisions on what is or is not necessary for the improvement or protection of navigation.In light of a very recent Supreme Court decision, however, there is some reason to believe that the courts may not automatically accept Congressional findings that a project benefits navigation or, to use the analysis favored in Kaiser Aetna, that it "substantially affects" interstate commerce.