As noted in a recent dispatch, measuring the impact of state photo ID laws presents certain challenges. There have been a few pieces of data from several states examining how many voters show up to cast a ballot without the proper identification. Recently, the National Conference of State Legislatures (NCSL) added to this picture with new data from Michigan.
The state requires voters to present photo ID at the polls. If they do not have the proper ID, they can instead sign an affidavit attesting to their identity and cast a ballot. During the state’s February 28, 2012 presidential primary 2,651 voters signed affidavits out of 1,216,310 total ballots cast—0.22 percent.
However NCSL notes that this number provides only a small picture of the impact of voter ID requirements. One important piece of information that is not currently available is how many voters do not show up to the polls in the first place because they do not have the proper ID.