Currently, Colorado citizens can register to vote using documents that establish their address – like a utility bill or paycheck – but don’t have to show photo ID.
Republican lawmakers argue that a photo requirement will fight voter fraud. Democrats object, saying that voter fraud is rare and arguing the bill will disenfranchise thousands of eligible voters, particularly the poor and elderly.
The bill passed the Senate on a party line vote. If it makes it into law, the photo ID requirement would be in effect for this fall’s presidential election. However, Democrats have a majority in the House. They've rejected several similar measures in recent years.
Across the country, more than 30 state legislatures have enacted similar laws in the last few years. The National Conference of State Legislatures says 11 states have strict requirements, while another 22 have non-strict rules.
Voter ID was a priority for Republicans after the party made major gains in the 2010 mid-terms, ProPublica reports. This year's election will mark a major test for many of those states as it will be the first major vote since their laws went into effect.