Demonstrators hold signs at an NAACP-organized rally on the steps...

Demonstrators hold signs at an NAACP-organized rally on the steps of the Pennsylvania Capitol to protest the state's new voter identification law in Harrisburg, Pa. (July 24, 2012) Credit: AP

Pennsylvania's voter ID law goes on trial this week. The first thing this challenge to the state's law has going for it are the real people who will testify about why it means they can't vote. The second thing is the Pennsylvania constitution. And the third is the utter lack of legitimate justification for the burdens the law imposes.

This law should go down, and now, before it can cause problems in November. But if you're a Democrat worried that the law -- which requires voters to show an approved form of photo ID at the polls -- is going to cost President Barack Obama the election, there's a possible silver lining. The number of voters affected may not be as huge, or as overwhelmingly Democratic, as it seems.

Let's start with the trial. The Talking Points Memo website and The New York Times have introduced us to 93-year-old Viviette Applewhite and 60-year-old Wilola Shinholster Lee. Applewhite has never had a driver's license, lost her Social Security card when her purse was stolen, and can't easily get a new one because she has changed her name twice to marry.

Lee -- who was born in Georgia but has lived in Pennsylvania since she was 5 years old -- lost her birth certificate in a house fire and she can't get another one. (According to the state of Georgia, her original birth certificate was lost in a fire there, too.) If it seems obvious that you need disenfranchised voters to challenge a voter ID law, it somehow wasn't in 2008, when the suit to block Indiana's law offered up no witnesses who said they'd find it hard to vote because of the new requirements.

The case, Crawford vs. Marion County Election Board, was actually a farce on both sides: Indiana couldn't present any evidence that the voter fraud the law was supposed to prevent existed. But Indiana's law wasn't as onerous as the new wave of voter ID laws, and in a decision by Justice John Paul Stevens six Supreme Court justices ruled that Indiana's law could stand. So you can see why Viviette Applewhite and Wilola Lee have a starring role this time around.

The precedent set by Crawford remains a stumbling block for the Pennsylvania plaintiffs, but not a huge one. That's because they are relying on the state constitution, which explicitly protects the right to vote -- a guarantee that is missing from our dear national founding document. Relying similarly on the Wisconsin constitution, two judges in that state recently struck down their onerous voter ID law, finding that its requirements were "unlikely to protect the electoral process," and substantially impaired the right to vote as guaranteed by the state constitution. The Missouri Supreme Court also tossed voter ID based on the state constitution in 2006.

Pennsylvania's defense of its law is especially weak. The Justice Department has launched its own inquiry into whether the law discriminates against minority voters. The state has already admitted that there have been no investigations or findings of in-person voter fraud in Pennsylvania -- the crime the law is designed to stop. That's right, not a single one. In a country with too little voter participation and too much apathy, it is just unconscionable that we would put people through the bureaucratic wringer to vote with absolutely no evidence of the harm this is supposed to stop.

Attorney General Eric Holder is right to call these laws poll taxes, invoking the ugly past of the Jim Crow South. It costs money to get the approved identification if you don't already have the obvious documents. And the motive for the laws now is just as suspect as then. Pennsylvania Republicans have done us the favor of making this clear, in the statement of state House Majority Leader Mike Turzai: "Voter ID, which is going to allow Gov. Romney to win the state of Pennsylvania - done."

What if it turns out, however, that the Republicans haven't dealt the utterly partisan blow they think they have? The state made headlines by announcing that as many as 759,000 Pennsylvania voters may not have the proper ID to vote, because they don't have a current driver's license. And about 185,000 of those people live in Philadelphia, a Democratic stronghold with a plurality of black voters. Obama won Pennsylvania by 600,000 votes; John Kerry beat George W. Bush by only 144,000. So hundreds of thousands of disenfranchised people this time around, with hordes of them in Philadelphia, would be big.

But there is data floating around that suggests that both the 759,000 and the 185,000 numbers may be significantly inflated. I got access to it only by promising not to say where it comes from, but the experts I was talking to read me numbers that disputed the well-known public figures. This data reportedly shows that between 60 and 65 percent of eligible voters, and a similar percentage of people who actually voted in 2008, don't have the right ID because their drivers' licenses have expired.

This expired-license group skews elderly and does not skew African-American.

Which suggests it may not be made up largely of Democrats, since older voters are more likely to be Republicans. Also noteworthy: While many of the voters without valid licenses live in Philadelphia and Pittsburgh, plenty also live in the suburbs -- where the GOP is strong.

It's possible, then, that if Pennsylvania's voter ID law goes into effect, there will be a lot of angry white, Republican, suburban voters turned away in November along with black Democrats like Viviette Applewhite. None of this makes voter ID laws one whit better. As drafted, with maximum hassle and zero proof that they're preventing real fraud, they're a scourge on our democracy, which is battered enough already. In general, they do burden minority and poor voters more than others, which should be the opposite of a selling point. And restrictive voting laws are in effect in other states where the presidential election could be close, including Florida, Iowa and Ohio.

But if it turns out that voter ID laws don't overwhelmingly tilt in favor of the Republicans who support them -- well, that would at least be a teeny bit satisfying. To the extent the party takes a political hit for disenfranchising people, it would be doing so for nothing. And then maybe we'd get rid of these bad laws, once and for all.

Writer Emily Bazelon is a Slate senior editor and writes about law, family and kids. She wrote this for