Arizona filed a lawsuit Thursday challenging the U.S. Voting Rights Act, which governs how it conducts its elections.

The landmark act, passed in 1965, outlawed discriminatory voting practices blamed for the widespread disenfranchisement of blacks, particularly in Southern states.

Arizona Attorney General Tom Horne, a Republican, said the section of the law requiring the state to get prior approval from the Justice Department for any changes to its election laws exceeds congressional authority and is unconstitutional.

The portions of the ... act requiring preclearance of all voting changes are either archaic, not based in fact, or subject to completely subjective enforcement based on the whim of federal authorities, Horne said in a statement.

In Arizona, Hispanics are the largest minority, accounting for nearly 30 percent of the state's population of 6.3 million, according to U.S. Census Bureau figures.

Horne said the state adopted bilingual ballots in 1974. The same year, it become only the second state in the nation to elect a Hispanic governor.

In pressing the suit, he said Arizona has been subjected to enforcement actions for problems that were either corrected nearly 40 years ago and have not been repeated, or penalized for alleged violations that have no basis in the Constitution. That needs to stop.

In response to the challenge, U.S. Attorney General Eric Holder said the Voting Rights Act plays a vital role in ensuring that every American has the right to vote and have that vote counted.

The Department of Justice will vigorously defend the constitutionality of the Voting Rights Act in this case, as it has done successfully in the past.

The provisions challenged in this case, including the preclearance requirement, were reauthorized by Congress in 2006 with overwhelming and bipartisan support. The Justice Department will continue to enforce the Voting Rights Act, including each of the provisions challenged today.