The New Deal had and continues to have many detractors among conservatives. Some conservative lawmakers saw New Deal spending projects as ways to ensure Washington spending helped a few people in Democratic districts—these pork projects would have less incentive to be effective since there would be no competition from the private sector. Conservatives in the Depression-era also saw New Deal projects as being too expensive. Many libertarian conservatives did not like the idea of government regulation of banks and the stock market. Others thought that price controls and government work projects took away the individual's incentive to work and find ways to increase personal income. Other conservatives, such as Justice Charles Evans Hughes, worried that the federal government was using the New Deal to establish too much power that would ultimately ruin the country.

Some liberals thought that the New Deal did too little. There was a great deal of interest in the Soviet Union during the 1930s, with many intellectuals coming back to the United States touting the Soviets' central planning economic model—of course, these American tourists were also not shown all the bad things going on inside the Soviet Union at the time. Some liberals, such as Huey Long, wanted to tax all the income of millionaires to provide every person money. Others wanted to plan a giant belt of trees in the Midwest to deal with the Dust Bowl, even though the region does not produce enough water to support many trees. Others wanted to see the New Deal expanded into education and healthcare.

Some of the complaints against the New Deal were justified. Healthcare and education costs still create an economic caste system in the United States that is hard to break, and millionaires have access to better accountants than middle-class taxpayers. New Deal programs such as Social Security and farm subsidies are still hotly debated topics in Washington. The most important criticism of the New Deal was that it did not end the Great Depression—by the end of the 1930s, unemployment was still over ten percent, numbers that are cause for alarm in modern politics. The New Deal was an appropriate plan despite its shortcomings in that it represented a policy shift that made the federal government more responsive to the needs of individuals. Regulations and insurance gave the public renewed faith in the banking and finance system—this would be important in the creation of retirement plans after WWII. The Tennessee Valley escaped endless cycles of destitution with the creation of the Tennessee Valley Authority. Most importantly, the New Deal gave the American public hope that the government cared about their needs and prevented the overthrow of capitalism in the United States. This is perhaps its greatest legacy, since Germany and Italy selected extremist leaders to improve their economies and world standing.