Rubin said the plaintiffs would show that a memo prepared by officials at the state Department of Aging and the Department of State had urged Gov. Corbett to expand the list of ID options available to voters under the new law.
"They were offered choices to make it easier or harder to vote, and almost invariably they chose to make harder," the Washington-based lawyer said.
Timothy P. Keating, a senior deputy attorney general representing the state, countered that the requirements are not "unduly burdensome."
"The sole issue relates to the constitutionality," he said. "Can it be implemented in a way that registered voters have liberal access to attain one if needed?"
Keating said that any voter in the state who wants to vote but lacks the other acceptable forms of ID, such as a valid driver's license, need only go to a Department of Transportation office with the proper documents to get a free photo ID card for voting.
He also said a law enacted by the legislature is presumed to be constitutional unless it is proved to "clearly, palpably, and plainly" violate the state constitution - which he said the evidence doesn't show.
Keating said special provisions have been made to help seniors, veterans, and college students obtain acceptable IDs. A special, free ID card for voters who lack a state driver's license or ID card issued by PennDot or other acceptable ID also is available through the Department of State.
During the trial's opening session, the plaintiffs presented recorded video testimony of two elderly women, both longtime voters with health issues. Both said they had limited access to transportation, had difficulty with long trips and the stair-climbing required to board a bus or get to a PennDot office, and did not think they could endure long waits in line once they got there.
"If I had to go to PennDot, I just wouldn't vote," said Mina Kanter-Pripstein, 92, who told of having cast her first vote for Franklin D. Roosevelt and now votes at a polling place downstairs in her senior-citizen apartment building in Philadelphia.
The other videotaped witness, Marian Baker, 71, of Reading, who is disabled by a leg injury, said that a family member helps her get to her polling place three blocks away, but that she had no one who could take her on the round trip of as much as five hours to the PennDot office in Berks County - nor could she bear to wait in line once she got there.
Baker said she was told in last November's election she would need an ID to vote in the May primary and did not go - "the first time in my life I did not vote," she said.
The law Corbett signed in March 2012 is considered one of the strictest in the nation and requires voters to show poll officials state-approved ID before the can cast ballots.
Non-driving voters may obtain a new voting-only ID at PennDot, but are barred from using IDs that do not have expiration dates, such as those used by military veterans and students at many colleges.
Rubin said the plaintiffs also plan to present testimony from statisticians who analyzed voter rolls and PennDot data to determine the percentage of the population that will be affected.
The trial is expected to last about two weeks, but many of those involved expect that however McGinley rules, eventual appeals are sure to put the law's fate before the state Supreme Court.
The plaintiffs - who include the Pennsylvania League of Women Voters, the NAACP, and Philadelphia's Homeless Advocacy Project, as well as several individual voters - had already succeeded in persuading courts to hold off enforcing the photo-ID requirement in last fall's presidential election and this spring's municipal and judicial primary.
Contact Amy Worden at 717-783-2584 or firstname.lastname@example.org or follow @inkyamy on Twitter.