For taxable years beginning on and after January 1, 2000, but before January 1, 2017, any individual shall be entitled to a credit against the tax levied pursuant to § 58.1-320 of an amount equal to 50 percent of the amount contributed by the taxpayer to a candidate, as defined in § 24.2-101, in one or more primary, special, or general elections for local or state office held in the Commonwealth in the taxable year in which the contributions are made. The amount of the credit shall not exceed $25 for an individual taxpayer or $50 for taxpayers filing a joint return.