Eccles arrived at these ideas not by any temperamental or cultural affinity—he was, after all, a banker and of Scottish descent—but by logic and experience. He understood the economy from the ground up. He saw how average people responded to economic downturns, and how his customers reacted to the deep crisis at hand. He merely connected the dots. His proposed program included relief for the unemployed, government spending on public works, government refinancing of mortgages, a federal minimum wage, federally supported old-age pensions, and higher income taxes and inheritance taxes on the wealthy in order to control capital accumulations and avoid excessive speculation. Not until these recommendations were implemented, Eccles warned, could the economy be fully restored.
Eccles then returned to Utah, from where he watched Roosevelt hatch the first hundred days of his presidency. To Eccles, the new president's initiatives seemed barely distinguishable from what his predecessor, Herbert Hoover, had offered—a hodgepodge of ideas cooked up by Wall Street to keep it afloat but do little for anyone else. "New York, as usual, seems to be in the saddle, dominating fiscal and monetary policy," he wrote to his friend George Dern, the former governor of Utah who had become Roosevelt's secretary of war.
In mid-December 1933, Eccles received a telegram from Roosevelt's Treasury secretary, Henry Morgenthau, Jr., asking him to return to Washington at the earliest possible date to "talk about monetary matters." Eccles was perplexed. The new administration had shown no interest in his ideas. He had never met Morgenthau, who was a strong advocate for balancing the federal budget. After their meeting, the mystery only deepened. Morgenthau asked Eccles to write a report on monetary policy, which Eccles could as easily have written in Utah. A few days later Morgenthau invited Eccles to his home, where he asked about Eccles's business connections, his personal finances, and the condition of his businesses, namely whether any had gone bankrupt. Finally, Morgenthau took Eccles into his confidence. "You've been recommended as someone I should get to help me in the Treasury Department," Morgenthau said. Eccles was taken aback, and asked for a few days to think about it.
"'Here you are, Marriner, full of talk about what the government should and shouldn't do,'" Eccles told himself, as he later recounted in his memoirs. "'You ought to put up or shut up. . . . You're afraid your theory won't work. You're afraid you'll be a damned fool. You want to stick it out in Utah and wear the hair shirt of a prophet crying in the wilderness. You can feel noble that way, and you run no risks. [But] if you don't come here you'll probably regret it for the rest of your life.'" Eccles talked himself into the job.
For many months thereafter, Eccles steeped himself in the work of the Treasury and the Roosevelt administration, pushing his case for why the government needed to go deeper into debt to prop up the economy, and what it needed to do for average people. Apparently he made progress. Roosevelt's budget of 1934 contained many of Eccles's ideas, violating the president's previous promise to balance the federal budget. The president "swallowed the violation with considerable difficulty," Eccles wrote.