By John Rondy
MILWAUKEE (Reuters) - The American Civil Liberties Union_on Tuesday sued the state of Wisconsin over its voter ID law, claiming it is unconstitutional and will deprive citizens of their basic right to vote.
The federal complaint seeks an injunction against enforcement of the voter ID law, which takes effect on February 21, 2012 for Wisconsin's spring primary elections.
The lawsuit is currently the only active federal challenge against a voter ID law, the ACLU said in a statement.
"This lawsuit is the opening act in what will be a long struggle to undo the damage done to the right to vote by strict photo ID laws and other voter suppression measures," said Jon Sherman, an attorney with the ACLU Voting Rights Project.
Opponents of the voter ID law have said they were concerned its requirements would result in residents who have been voting for decades being turned away from the polls including veterans, minority voters and seniors as well as the homeless.
The law requires voters to present identification, such as a driver's license or a passport, when they cast ballots in federal, state and local elections. The law will be enforced for the first time in February, when Wisconsin voters head to the polls to cast ballots in spring primaries.
Cullen Werwie, a spokesman for Wisconsin Governor Scott Walker, a Republican elected in 2010, said the "common sense election reforms" were constitutional.
"Requiring photo identification to vote helps ensure the integrity of our elections -- we already require it to get a library card, cold medicine, and public assistance," he said.
Thirty-one states now require voters to show some form of ID before voting, according to the National Conference of State Legislatures website. In 15 of those, including Wisconsin, the ID must include a photo of the voter.
Advocates of the laws, which have passed this year in Alabama, Kansas, Rhode Island, South Carolina, Tennessee and Texas, say they are needed to combat voter fraud. Opponents say there is no evidence of widespread fraud.
The ACLU's challenge came as the Wisconsin Government Accountability Board, a state election watchdog, prepared a statewide advertising campaign with television and radio spots to educate residents on the new law and where they may obtain the proper photo identification for free.
The TV and radio ads are expected to begin running in January and are planned to run for a total of 28 weeks leading up to elections in February, April, August and November at a cost to the state of about $252,000 to air.
The campaign also will use print and billboard ads, a texting program, a newly-created bringit.wisconsin.gov web site and Internet banner ads directing people to the web site.
The Wisconsin law already has been challenged in the Dane County Circuit Court by the League of Women Voters.
(Additional reporting by Brendan O'Brien; Editing by Mary Wisniewski and Jerry Norton)