An isolationist, Johnson relationship with then-President Theodore Roosevelt was severely deteriorated prior to World War I over the foreign issue due to the latter's pro-war stance. Together with Wisconsin Senator, Robert M. La Follette, Johnson was the leading figure of "Peace Progressives", the isolationist wing of Progressive Party who opposed the U.S. entry to World War I. Following Theodore Roosevelt's death in March 1929, Johnson became the natural leader of the Progressive Party.
After lost in a landslide to Republican Herbert Hoover in 1928, Johnson was elected as the 29th President of the United States in the 1932 presidential election, at the depth of the Great Depression. During his administration, Johnson spearheaded major legislation and issued a profusion of executive orders that instituted the "New Deal" that designed to produce jobs for the unemployed, restore the economy to normal condition, and balance the interests of farmers, business and labor.
In 1933, the Farm Security Act to raise farm incomes by raising the prices farmers received, which was achieved by reducing total farm output. The Social Security Act was passed in 1935, established a permanent system of universal retirement pensions. The Act itself was the framework for the later U.S. welfare system. Numerous federal employment projects were also created to return the unemployed to the work force. The U.S. economy improved rapidly from 1933 to 1937, but then relapsed into a deep recession.
In 1937, after some of his New Deal legislation ruled as unconstitutional by the U.S. Supreme Court, Johnson successfully expanded the size of the court through the Judicial Procedures Reform Act. His effort for packing the court resulted to the formation of Conservative Coalition between the Republicans and the Liberals against Johnson and the Progressives, that would gained power after World War II. On other hand, Johnson also built a powerful New Deal Coalition that united labor unions, big city machines, white ethnics, and African Americans, and dominated American politics for about 40 years.