While New York’s political class has been focused on Albany as it heads down the homestretch for the 2015 legislative session, the US Supreme Court could have a huge impact on both the state’s policies and politics.

Last week, the Supreme Court agreed to hear a case brought by some voters in Texas that could define the meaning of the principle of “one person, one vote.”  The Court is expected to reach a decision next year.

We all know that in our representative democracy, it’s important that legislative districts contain more or less the same number of people; we all want equal representation.  That’s why the nation has had a census – it’s a way to count the number of people in the nation and then to allocate Congressional districts to reflect changes in the population.

The Constitution itself is quite clear:  the 14th Amendment states that all people in the United States are to be counted for distributing US representatives.

A 1964 Supreme Court decision ruled that voting districts must contain very close to the same number of people. But the court did not say which people count.

Federal appeals courts have uniformly ruled that counting everyone is permissible, and one court has indicated that it is required.  The census counts every person living in the nation, irrespective of their ages, whether they are immigrants – here legally or not.   And it is that census that provides the basis for the reapportionment of Congressional representatives and the drawing of new district lines every ten years.

But the Supreme Court has never resolved whether voting districts should have the same number of people, or the same number of eligible voters. Counting all people amplifies the voting power of places with large numbers of residents who cannot vote legally, including immigrants who are here legally but are not citizens, illegal immigrants, children and prisoners.

And that issue – who counts when creating legislative districts – is at the heart of the case brought in Texas.

Most state and local governments draw districts based on total population. If people who were ineligible to vote were evenly distributed, the difference between counting all people or counting only eligible voters would not matter. But demographic patterns vary widely.

Not only is there the obvious issue of counting those under the age of 18 – clearly nonvoters – but there is the issue of immigrants living in the country.  For example, there are about 11.7 million illegal immigrants that lived in the United States in January 2010.  More than half of all unauthorized immigrants lived in California (2.9 million), Texas (1.6 million), Florida (1.0 million), and New York (705 thousand).

More broadly, more than four million immigrants live in New York and three million of them live in New York City.  Roughly the same proportion of illegal immigrants live in New York City, so more than 550,000 illegal immigrants live in the City.

The Texas case argues that the definition of “one person, one vote” means only voters.  The individuals bringing the case argue that their voting power had been diluted.  They argue that their representatives should have more of a say since they are from rural areas which tend to have higher numbers of older voters and with a smaller percentage of immigrants.

So, what are the arguments?  The current system ensures representational equality, with elected officials tending to the interests of the same number of people, whether they are voters or not. Counting only eligible voters, on the other hand, is based on the principle that voters hold the ultimate political power in our democracy.

If the challenge succeeds, it is likely to hurt urban areas – with its larger immigrant populations and with a younger average age – and benefit rural areas.

But more problems could result: The change would likely mean new districts would have to be developed, but that would require a new census, since the current one includes all people, of all ages.

And redoing legislative districts and then holding new elections could make Albany even more chaotic than it is now.  New York’s political future is in the Court’s hands.