A state may make contracts with individuals, and such contracts when made cannot be impaired, although as already indicated (see above, § 264) there may be no remedy afforded for the violation of the contract by the state. But a general statute does not constitute a contract, and one who relies upon such statute must do so with the understanding that the legislature which made it may repeal it at discretion. A state cannot contract away or impose limitations upon its general power to legislate for the public benefit. Thus if, while a state statute is in force providing that members of voluntary fire companies or militia organizations shall not be required to pay poll taxes, a person becomes a member of such organization, he cannot afterwards complain if the general statute in this respect is changed and the privilege is withdrawn. Statutory exemptions from taxation are therefore repealable (Salt Company v. East Saginaw).

Where an office is created by statute it may be abolished, and the incumbent thereby deprived of the privileges and emoluments of such office without the violation of any contract right. But the state cannot take away the right to recover compensation already earned by performing the duties of the office, for here the right is already accrued and has become complete as a property right of which the officer cannot be deprived without due process of law (Fisk v. Jefferson Police Jury).