Taxpayer Protection Act of 2020 This bill directs the Department of the Treasury to establish the Taxpayer Protection Program to provide forgivable loans to state, territory, tribal, and local governments to cover revenue losses caused by the COVID-19 pandemic and for other specified purposes. Specifically, loan amounts received under this bill may be used (1) to cover revenue losses caused by business interruptions, unemployment, or other economic hardship directly caused by the COVID-19 pandemic; and (2) for infrastructure or essential government service expenditures, including all general operating expenses. However, they may not be used for the service of any debt obligation or unfunded liability for employee retirement benefits. The bill permits loan forgiveness if a state or local government meets specified requirements, such as a state having a truly balanced budget, sufficient rainy-day funds, and sound pension funds (i.e., pension funds that are based on generally accepted actuarial principles and that meet other specified requirements).