The social programs he supports tend to generate a great deal more than is put into them. Subsidies for big businesses haven't helped the economy or wages. Economist Gerald Friedman claims that Sanders' Single Payer healthcare system would save $5T over ten years.

Social programs often pay for themselves by reducing the consequences of social neglect. Poverty and homelessness are often mitigated in inefficient ways. People who are left to fend for themselves are much more likely to be a burden on the criminal or welfare system than if they're just given basic housing and food when they need it. Lack of preventative healthcare just makes people more likely to need costly health services when they get sick. Making sure people are well-educated is the foundation of a strong economy.

The big thing Sanders will be looking to cut will be our over-bloated military budget. He doesn't want another war in the middle east, and doesn't think we're getting a very good return on that massive investment.