From the introduction for U.S. Constitutional Limits on State Money-Bail Practices for Criminal Defendants (R45533, Feb. 26, 2019):
Courts have heard legal challenges regarding whether state or local money-bail systems comport with the Constitution’s Due Process and Equal Protection Clauses. The Supreme Court has established that the Constitution provides certain protections to indigents during sentencing and postconviction, including ensuring that an indigent’s failure to pay a fine cannot result in an automatic revocation of probation or imprisonment beyond the statutory maximum term. The Court, however, has not addressed these rights in the bail context. Applying the rational basis standard, some courts have found money-bail systems that reasonably ensure a defendant’s subsequent court appearance to be constitutional. Other courts have indicated that bail systems that detain indigent criminal defendants pretrial, without considering their ability to pay, may be unconstitutional.