A Pennsylvania judge has declined to suspend a Pennsylvania voter identification law that the White House has scrutinized for potentially disenfranchising voters.

Commonwealth Court Judge Robert Simpson said he would not grant an injunction to prevent the law, which requires voters to present government-sanctioned identification, from taking effect.

The voter ID measure is one in a wave of new voting laws emanating from Republican-led legislatures across the country, and a familiar narrative has unfolded in Pennsylvania: Republicans defend the law as a safeguard against fraud at the polls, while Democratic critics say the law disproportionately burdens low-income, minority and elderly voters who are unlikely to have proper identification.

Formerly, Pennsylvania voters could identify themselves with a range of documents that included utility bills and bank statements. But the new law restricts the type of identification that is acceptable, prompting the Department of Justice to question Pennsylvania about how many people lack necessary ID in a letter that raised concerns about potential violations of the Voting Rights Act.

Some of the plaintiffs suing to block the law's implementation argued that in addition to lacking a government-issued photo ID, they did not have the necessary documents, such as a birth certificate, to obtain one.

Pennsylvania's status as a large swing state has amplified concerns that the new law may distort the results of the upcoming presidential election. Critics argue that the types of voters who are less likely to have proper ID are also groups that traditionally lean Democratic.

The Republican majority leader of the Pennsylvania's House of Representatives underscored that point when he said that the voter identification law would "allow Governor Romney to win the state of Pennsylvania," a statement opponents of the law have seized upon as proof that the voter ID measure has partisan motives.

Witold J. Walczak, an American Civil Liberties Union lawyer who helped argue the case, told the Associated Press that he would be appealing Judge Simpson's decision.

"We're not done," Walczak said. "It's not over."