What is the major source of revenue for both the national government and most states?

The major source of revenue for both the national government and most states is primarily derived from income tax. This form of taxation is significant because it directly taxes individuals and entities based on their earnings or profits, making it a substantial source of funding for government operations and public services.

At the federal level, income tax is critical as it accounts for a large portion of federal revenue, funding essential services such as national defense, social security, and education. Similarly, many states rely heavily on income tax collections to support state programs, infrastructure, and services for their residents.

The income tax structure allows for progressive taxation, where those with higher incomes pay a higher rate, contributing significantly to overall revenue availability for various government functions. This progressive nature helps to balance resource distribution across different socioeconomic groups, thereby providing vital services to a broader demographic.

While other sources of revenue, such as property tax, sales tax, and excise tax, contribute to government revenue, they typically do not overshadow the significance and scale of income tax collections at both the national and state levels.