Voter ID laws have become a hot-button issue leading up to the November presidential election, pitting state legislatures proposing and sometimes passing such laws against civil rights advocacy organizations who argue the laws are designed to keep minorities from the ballots.

In issuing their 56-page opinion Thursday, the judges wrote that the Texas law likely would have a "retrogressive effect" on the ability of minority voters to cast ballots and said the "implicit costs" of obtaining necessary ID "will fall most heavily on the poor." The three-judge panel also noted that a disproportionately high percentage of African Americans and Hispanics in Texas live in poverty.

Texas and other proponents of voter ID laws say the measures are necessary to prevent voter impersonation or fraud. Last year, Kansas, Mississippi, Rhode Island and Wisconsin passed new voter ID laws while Texas, South Carolina, Alabama and Tennessee tightened existing laws.

Governors in Minnesota, Missouri, Montana, New Hampshire and North Carolina vetoed strict new voter ID laws. This week, South Carolina's law is on trial in front of a three-judge panel in the same federal courthouse where the Texas law was struck down.

Civil rights organizations have argued that minority voters are less likely to have picture IDs, less likely to be able to afford new photo IDs and, in some cases, older minority voters might not have been granted the birth certificates required to obtain some forms of photographic identification.

The judges in Washington reviewed the Texas measure after the state appealed a rejection from the Justice Department, which is required to review proposed voting laws in Texas and other states and jurisdictions that have a history of voter discrimination.

The office of Texas Attorney General Greg Abbott said the state would appeal the decision to the U.S. Supreme Court.

"Today's decision is wrong on the law and improperly prevents Texas from implementing the same type of ballot integrity safeguards that are employed by Georgia and Indiana and were upheld by the Supreme Court," the statement said, referring to voter ID measures in those two states that passed Supreme Court challenges.

The office of Gov. Rick Perry issued a bristling statement that read, "Chalk up another victory for fraud. Federal judges subverted the will of the people of Texas."

The Department of Justice opposed the Texas law because, the agency said, it would have required many people without the proper voter identification to travel long distances in order to get one and, in some cases, pay for the documents they might need to secure that ID.

"When a jurisdiction meets its burden of proving that a proposed voting change would not have a racially discriminatory purpose or effect, the Department will not oppose that change," Attorney General Eric Holder said in a statement. "When a jurisdiction fails to meet that burden, we will object."

The head of the Texas State Conference of the NAACP, which presented evidence before the judges against the proposed law, said the decision proves the need for Section 5 of the Voting Rights Act, which requires preclearance.

"The (Texas) law was so broad and unreasonable that clearly its goal was to suppress minority votes," Gary Bledsoe, conference president, said.

A representative for the Lawyers' Committee for Civil Rights Under Law said no one is saying they are in favor of voter fraud, but added that the state's current law, which allows some non-photo identification for voters, already prevents fraud.

"That's sort of a solution in search of a problem," Bob Kengle, co-director of the committee's Voting Rights Project, said of Texas' position.

The Texas secretary of State issued a statement Thursday saying the election would proceed under current state law.