Based on this excerpt, we can infer that Roosevelt believed the government should control businesses operating across state lines, hoped that congress would strengthen the laws against monopolies, and was upset that laws preventing the formation of monopolies had failed.
This is indicated by several elements in the text.
- First of all, Roosevelt starts by saying "we must have government supervision of ... all corporations doing interstate business," which clearly states his intention to control business activities which extend beyond a state's borders.
- He deplores the failure to ban monopolies: "The effort at prohibiting [monopolies] has failed." Roosevelt was a progressive, he believed in government intervention to regulate the economy. While he never opposed capitalism, he was strongly against monopolies.
- He wants to strengthen the Interstate Commerce Commission and the enforcement of the Hepburn Act: "we must go yet further." The Interstate Commerce Commission (ICC) was created in 1887 to regulate shipping rates on interstate trade routes, in a way that would boost fair competition. The Hepburn Act of 1906 extended the ICC's juridsdiction to not only include railroads and bus/truck roads, but also bridges, ferries, and oil pipelines for example. By giving the ICC more power over corporations' finances, the government would have an increased control over shipping regulations.