Final answer:
The text structure in President Wilson's message to Congress is 'main idea and details,' which separates the actions of the German government from its people and further elaborates the main idea with supporting details about the nature of government decisions leading to war.
Step-by-step explanation:
The text structure used to support the viewpoint in President's Wilson's message to Congress is d) main idea and details. The main idea presented in the excerpt is the separation of the German people from the acts of their government, emphasizing a sympathetic view of the German populace. Detailed points support this viewpoint by discussing how the war was not prompted by the will of the German people, but by the ambitions of their rulers, reminiscent of old dynastic wars.
President Wilson's position towards World War I and the U.S. entry into it was marked by an appeal to moral principles and democratic ideals, aiming for a peace that would be just and last beyond the immediate conflict. His later Fourteen Points speech encapsulated his view that the war should end with a peace that addressed the root causes of the conflict—a view that was idealistic and not immediately embraced by his counterparts in Europe who had suffered more directly.