Thirty-one states require all voters to show ID before voting at the polls. Laws can be broken down into three categories:

• Strict photo ID (Georgia, Indiana, Kansas, Wisconsin, South Carolina, Tennessee, Texas, Mississippi): Voters must show a photo ID in order to vote.

• Photo ID (Alabama, Florida, Hawaii, Idaho, Louisiana, Michigan and South Dakota): Voters are asked to show a photo ID in order to vote, or they must meet certain other criteria. In some states, a voter with ID can vouch for one without.

• Non-photo ID (Alaska, Arizona, Arkansas, Colorado, Connecticut, Delaware, Kentucky, Missouri, Montana, North Dakota, Ohio, Oklahoma, Rhode Island, Utah, Virginia, Washington): All voters must show ID at the polls, but also acceptable are a utility bill or bank statement with voter's name and address.

Source: National Conference of State Legislatures