Barely a trickle of voters dripped into polls today in Pennsylvania, despite the chance to finally weigh-in on the presidential primary, with Republicans facing a choice of Newt Gingrich, Ron Paul or Mitt Romney.

But the real contest is possibly the outcome when potential voters are asked to produce a picture ID for the first time before pulling the lever. The ID could be an issue for thousands of residents without drivers licenses, particularly in the city where public transportation is a norm. A new state law requires voters to produce photo IDs by the November 6 general elections.

Already, some voters are grumbling about the law, while others simply greeted it with a shrug.

Many poll workers are using today as a dry run today and asking potential voters to prove they are official Commonwealth citizens until voting booths close at 8 p.m. Accepted forms of photo ID include a Pennsylvania driver's license, a non-driver's license photo acquired at a PennDot office, U.S. Passport, military ID, government employee photo ID, college ID, or photo ID cards issued by a care facility.

If you are blocked from voting, you can call 215-686-3461.

Voters will be allowed to cast ballots in the primary whether or not they have the appropriate ID. But those without ID in the Nov. 6 general election will have to cast provisional ballots that will only be counted only if the voter provides proper identification to county officials within six days.

It might be a good day for a test of a new system. Turnout is expected to be low without a major contested race to compel voters to the polls, especially with Romney facing little real competition since former Pennsylvania Sen. Rick Santorum dropped out two weeks ago. President Obama is unopposed.

But voters will be faced with a choice in the primary race for attorney general, with Democrats Kathleen Kane, a former Lackawana County prosecutor, and former U.S. And Rep. Patrick Murphy of Bucks County vying to get on the November ballot to face Republican David Freed. The Kane-Murphy race is arguably the hottest statewide race.

And five are competing for the Republican nomination to challenge Democratic U.S. Sen. Bob Casey's re-election bid: Steve Welch, a Chester County entrepreneur who is endorsed by the state GOP; Tom Smith, a wealthy former coal company owner from Armstrong County; ex-state Rep. Sam Rohrer of Berks County; suburban Harrisburg lawyer Marc Scaringi; and David Christian of Bucks County.

In the state Legislature, only four incumbent senators, out of 25 districts open this cycle, have primary opponents, while in the House only 28 incumbents could be defeated. Also, voters will fill six vacant state House seats in special elections concerning one district each in Allegheny, Lehigh and Montgomery counties, and three in Philadelphia.

Indeed, turnout has been light so far today, according to observations at various polling places.

By 9:30 a.m., only 61 people had voted at Roberts Elementary School, in Wayne.

GOP poll-worker Dave Furman said he knew nothing about the voter ID law.

But, Kathy Brown, the judge of elections, said the voters who have shown up knew all about it, and that no one balked when asked for ID.

"We'll have more issues in November," Brown said.

At Swedeland Fire Co., in King of Prussia, only 13 people had shown up by 10 a.m., according to poll worker Gene Lonchar, who was seated on a folding chair by a coffee-maker and a bank of empty voting machines. That number represents about 1 percent of eligible voters. Lonchar said the voter ID was a non-issue because showing ID is a habit among locals.

"People show their IDs any way," Lonchar observed. "They view voting like so many other of life's pleasures. "You need ID to drive a car, for everything else."

That said, Cindy Ryan, the election judge said voters there were familiar with the law, and no one had expressed objections.

However, Lorna Carroll, 87, strongly disapproves of the new voter identification law. She purposely left both of her proper voter IDs inside her residence in Wynnewood's Green Hills Apartments before casting her ballot at a polling place setup at the complex.

"I wanted to protest this voter ID law, which I think is incredibly unfair," said Carroll, a Democratic committeewoman for Green Hills. "It's unfair to many groups, especially to people are not mobile and who don't have a lot of opportunities to go through the headache to get proper ID."

Similarly, turnout was sparse at Green Hills Apartments, as it was at other nearby polling locations, including Lower Merion's Penn Valley Elementary School and the Annunciation Church in Havertown. By 10 a.m., only 30 of the more than 1,000 residents in Green Hill's voting Precinct 1 went to the polls.

Why? Maybe Green Hills resident Charlotte Getter had the answer. Getter said that after she voted, she ran into a handful of friends and neighbors who had no idea there was an election today.

In Philadelphia, at polling places in Fishtown and Kensington, election judges reported few problems. Judges at three locations said they were asking everyone for ID, even the voters they had known personally for years. "We just want to get them ready for November," said Elaine Feulner, at the Neumann North apartments on Frankford Avenue.

Feulner said that "99 percent" of the voters they got that morning had ID. People seemed aware of the new law for the most part, and she said that one voter even mentioned that they had obtained a photo ID for the purpose of voting. The few people who did not were given information about the new law, Feulner said.

Election judge Darlene Hawthorne said she felt the new regulation was unfair to seniors who live on fixed incomes.

"They don't want to spend money on getting something like that," she said. "I think it should be acceptable to show their Social Security card or something else."

Voter Sagan Medvec, who moved to the neighborhood about four years ago, said he wasn't aware of the new law but that he has always brought ID to show at the polls.

"If they're going to make voter ID mandatory, maybe the government should issue it to people for free," he said.

At 2424 Studios on York Street, in Kensington, the problem wasn't that people didn't know about the new ID requirement – it was that many voters apparently hadn't heard about the new polling location. This year the polling moved from its longtime location at Luke's Bar, on the 2400 block of Cedar, to the cavernous studio space about 3 blocks away. By 10:30 a.m., election judges said only 15 people had shown up – a significant drop from the normal crowd of neighborhood residents who usually turn out.

"There's no signs at the other place, nothing," said Judy, a longtime election judge who declined to give her last name. "Nobody knows it's here. We want to go back!"

At polling places in Chestnut Hill and Roxborough, poll workers asked to see ID from neighbors they already recognized, gave a once-over to their PennDOT photographs, distributed state-approved handouts on the new voter-ID requirements and then ushered people to voting machines.

Most everyone had identification, but a few chose not to show it – on principle. One woman, described as a feisty Democrat in her late 80s, declined to show anything to poll workers, saying that "she purposely didn't bring it, as a matter of protest," said an election judge at Cathedral Village, a retirement community in Roxborough's 21st ward. "We explained that we'd have to follow the law in November. She'll be willing, she absolutely understands."

A younger woman, a Republican in her 50s, appeared at the same polling place, displayed her ID and said, "It's about time they put that thing [voter ID] into effect," according to majority inspector Don Mechlin, one of the division's poll workers.

Several women who showed up to vote at Cathedral Village expressed concern about older relatives living with them. "One woman said her mother is 101 years old. She can't get her birth certificate and her only ID is an expired driver's license," said Kathryn Bagley, a majority inspector.

Although the 101-year-old woman would have been allowed to vote Tuesday without identification, her daughter left her at home, wanting to avoid any hassle at the polls. "At 101, you want to keep her life as ascetic as possible," Bagley said.

If you're voting today, some helpful links:

-Find your polling place .

-Learn about the voter ID law or call the election hotline 1-866-OUR-VOTE (1-866-687-8683), an election protection hotline run by the Committee of 70 and the Pennsylvania Voter ID Coalition.

-Visit the voters guide here.

The Associated Press contributed to this story.