I just did a quick read of Stevens' opinion.
[E]ven rational restrictions on the right to vote are invidious if they are unrelated to voter qualifications... [H]owever, we [have] confirmed the general rule that "evenhanded restrictions that protect the integrity and reliability of the electoral process itself" are not invidious... Rather than applying any "litmus test" that would neatly separate valid from invalid restrictions,. a court must identify and evaluate the interests put forward by the State as justifications for the burden imposed by its rule, and then make the "hard judgment" that our adversary system demands.
While petitioners argue that the statute was actually motivated by partisan concerns and dispute both the significance of the State's interests and the magnitude of any real threat to those interests, they do not question the legitimacy of the interests the State has identified.
The first is the interest in deterring and detecting voter fraud. The State has a valid interest in participating in a nationwide effort to improve and modernize election procedures that have been criticized as antiquated and inefficient. [See National Commission on Federal Election Reform, To Assure Pride and Confidence in the Electoral Process 18 (2002) (with Honorary Co-chairs former Presidents Gerald Ford and Jimmy Carter).]
It remains true, however, that flagrant examples of such fraud in other parts of the country have been documented throughout this Nation's history by respected historians and journalists, that occasional examples have surfaced in recent years, and that Indiana's own experience with fraudulent voting in the 2003 Democratic primary for East Chicago Mayor - though perpetrated using absentee ballots and not in-person fraud - demonstrate that not only is the risk of voter fraud real but that it could affect the outcome of a close election.
There is no question about the legitimacy or importance of the State's interest in counting only the votes of eligible voters. Moreover, the interest in orderly administration and accurate recordkeeping provides a sufficient justification for carefully identifying all voters participating in the election process. While the most effective method of preventing election fraud may well be debatable, the propriety of doing so is perfectly clear.
http://www.scotusblog.com/wp-content...8/04/07-21.pdf
