Iowa Senate approves constitutional amendment requiring flat income tax rate

The Iowa Senate has approved a constitutional amendment that would require Iowa to have a flat individual income tax rate — if the state imposes an income tax at all. The Senate voted 34-15 Tuesday to pass Senate Joint Resolution 2004, with every Republican in favor and every Democrat opposed. The proposal would require an individual income tax imposed by the state to be a single rate. It would forbid having a graduated income tax system with multiple rates based on income level. If the proposed amendment passes the House...