You would think that this issue was settled already:
WASHINGTON The Supreme Court upheld Indianas voter-identification law on Monday, declaring that a requirement to produce photo identification is not unconstitutional and that the state has a valid interest in improving election procedures as well as deterring fraud.
Text of the Opinion
In a 6-to-3 ruling in one of the most awaited election-law cases in years, the court rejected arguments that Indianas law imposes unjustified burdens on people who are old, poor or members of minority groups and less likely to have drivers licenses or other acceptable forms of identification. Because Indianas law is considered the strictest in the country, similar laws in the other 20 or so states that have photo-identification rules would appear to have a good chance of surviving scrutiny.
http://www.nytimes.com/2008/04/29/washington/28cnd-scotus.html?_r=0
I think the DOJ suit is all about publicity, not law. In the court, they will have their butts handed to them. Politically, it will be used as “proof” that racist America hates blacks...