Ten registered voters, including five Philadelphians, contend in a lawsuit that the law will deny their voting rights. They want the law blocked while judges consider its constitutionality. The law, among the nation's toughest, would require voters to present a valid photo ID before they can cast ballots.
The hearing could last a week.
Democrats contend that the law will suppress votes of seniors, students, minorities and low-income residents, and especially those who don't drive. A July 17 study by the Brennan Center for Justice at New York University's Law School said 985,414 voting-age citizens in Pennsylvania do not have access to a vehicle.
Republicans say the law is needed to ensure that only eligible voters vote.
Closer to home, a judge of elections in a precinct in tiny Colwyn borough told the Delaware County Times Thursday that he "will not comply with the new voting law because it is unconstitutional."
Christopher L. Broach Sr., a Democrat, said he would abide by the requirements of the old law, which did not require a photo ID.
"I am taking the stand against the new Republican voter law and hoping that anyone nationally whom has been elected to an office with the title of judge will do just that," Broach said.
Meanwhile, in Washington, House Republicans on Thursday criticized the Justice Department's decision to challenge new voter-ID laws in South Carolina and Texas.
"The Department of Justice has embarrassed itself," said Rep. Trent Franks, R-Ariz. "The partisan bias is obvious." Thomas Perez, the department's chief civil rights enforcer, denied any partisan bias or motivation. Justice indicated earlier this week it also is looking at whether Pennsylvania's new law violates the Voting Rights Act, a 1965 law for ensuring minorities' right to vote.
The Associated Press contributed to this report. Contact Michael Hinkelman at 215-854-2656 or hinkelm@phillynews.com. Follow him on Twitter @MHinkelman.