An 1869 ruling used by a Pennsylvania state judge in August to uphold a tough new voter ID law is providing some new and startling historical context to deliberations by the Pennsylvania Supreme Court, as it mulls whether to block the controversial law before the Nov. 6 presidential election.

Looking specifically at the tumult and vagrancy of 19th century city life in Philadelphia, the so-called 1869 Patterson v. Barlow decision, which in part allowed election officials to consider a voter’s “virtue” before being allowed to cast a ballot, formed the backbone of Judge Robert Simpson’s decision last month that the new law was constitutional and could go into effect immediately. The original Patterson ruling was written by state Supreme Court justices, whose legal descendants are now weighing the voter ID law.

The ruling was more of a legal side note in the actual hearing Thursday. But citation of the ruling, which used what today would be considered by many to be bigoted language to justify early curbs on the franchise, has hit a nerve among critics who say Judge Simpson’s reliance on the ruling ties modern day critiques of voter ID laws directly, and shockingly, to a historical narrative of “anachronism and … outright prejudice,” according to one legal brief filed in the case.

The Patterson decision “shows that a majority of the Pennsylvania Supreme Court was once led to rationalize burdensome election procedures based on generalized and biased fears about fraudulent voting. That historic mistake should make the court hesitate to uphold another election law ostensibly aimed at preventing fraud when the state has offered no evidence that any such fraud has actually occurred,” writes Jessie Allen, a law professor at the University of Pittsburgh, in the Pittsburgh Post-Gazette.

Painting a colorful Dickensian view of old Philadelphia, the 1869 court wrote, “Where the population of a locality is constantly changing, and men are often unknown to their next-door neighbors; where a large number is floating upon the rivers and the sea, going and returning and incapable of identification; where low inns, restaurants and boarding-houses constantly afford the means of fraudulent additions to the lists of voters, what rule of sound reason or of constitutional law forbids the legislature from providing a means to distinguish the honest people of Philadelphia from the rogues and vagabonds who would usurp their places and rob them of their rights?"

For emphasis, the court further explained that to deny the tougher voting rules for Philadelphia voters “would be to place the vicious vagrant, the wandering Arabs, the Tartar hordes of our large cities, on a level with the virtuous and good man.”

To many Americans, that language reeks of contempt for society’s have-nots even as its intent – to protect the franchise from fraud – has a contemporary political ring.

“The use of Patterson as legal precedent is particularly relevant, because opponents of the law allege that the current Pennsylvania legislature is similarly trying to use the law to prevent certain people from voting – in this case, demographic groups that tend to vote Democratic,” writes Dan Froomkin on the Huffington Post.

To be sure, legal experts say the Supreme Court justices can find plenty of other reasons than 143-year-old legal writs for upholding or reversing Judge Simpson’s decision.

Moreover, Simpson did not rely on the controversial wording in Patterson to make his decision, instead citing a passage that says the discretion to secure the vote "belongs to the General Assembly, is a sound one, and cannot be reviewed by any other department of the government, except in a case of plain, palpable, and clear abuse of the power which actually infringes the rights of the electors."

“Based on the availability of absentee voting, provisional ballots and opportunities for judicial relief … for those with special hardships, I am not convinced... [Pennsylvanians] will not have their votes counted,” Judge Simpson finally ruled.

Supporters of the law say the contemporary impact of the law doesn’t carry any of the prejudice and xenophobia expressed by 19th century Supreme Court justices in the Patterson decision.

The Pennsylvania General Assembly “has not caused anyone to be disenfranchised. Nor has it changed the qualifications set forth in the Pennsylvania Constitution,” the conservative group Judicial Watch writes in a friend-of-the-court brief. “Rather it has maintained and promoted free and equal elections."

Seventeen states have strict voter ID laws and five more have laws being held up on federal and civil challenges. Mostly Republican legislatures have voted to firm up voting rules to curb perceptions of voter fraud, while most Democrats say that the rules disenfranchise some of their base support, namely minorities, the poor, and the elderly.

The Pennsylvania voter ID law could affect over 700,000 potential voters who currently don’t have an ID, but state lawyers convinced Judge Simpson that the barriers to getting a state-issued ID to vote weren't so onerous as to actually curtail voting rights. The state Supreme Court justices, divided evenly between Republicans and Democrats, were not expected to make their ruling Thursday.