The Supreme Court heard oral arguments Tuesday in a case that could have serious implications for congressional representation. In the 1960s, the Supreme Court ruled that the 14th Amendment guaranteed a principle that became known as “one person, one vote.” In other words, legislative districts must be drawn with equal populations. Now, the question is whether that means general or voting population, and whether clusters of illegal immigrants dilute the power of legitimate voters.

Evenwel v. Abbott was brought by two Texas residents who argue that the power of the vote in their districts is diluted because of disparities due to the distribution of the non-voter population — in this case illegal immigrants. Each state legislative district in Texas has 811,000 total people, regardless of their eligibility to vote. Titus County, one of the districts in question in this case, has 574,000 eligible voters. The nearby rural district that encompasses the city of Brownsville has 372,000 eligible voters. This means that a vote from Titus county carries two-thirds the weight of a vote in Brownsville.

One of the main reasons for this disparity is the distribution of illegal immigrants in Texas and other states. Illegals tend to gather in close proximity to one another, thus skewing the total population and therefore congressional representation.

The Supreme Court has frequently sided with the voters in these matters. Reynolds v. Sims in 1964 was one of the most important tests of one-person, one-vote, and in 1966 the Court again sided with the voters in Burns v. Richardson. In both cases, it was made clear that when the total population diverges from the number of eligible voters, representation should follow the voters.

However, we no longer have that kind of Supreme Court. The Roberts Court is highly politicized, motivated by demands other than upholding Rule of Law, and weak when it comes to affirming or establishing precedent.

Texas state officials and the Obama administration already claim that they have no way of determining how the illegal immigrant population breaks down from district to district. The U.S. Census, however, estimates the number of illegal immigrants through house-by-house counting. This information can surely be brought to bear in a calculation that measures the power of the vote from one district to the next.

Politicians will surely not want to redraw districts if it means a redistribution of House seats away from areas with large illegal populations. (That means you, Texas, Florida, California and New York.) As The Heritage Foundation’s Hans von Spakovsky observed, “If the Court finds that Texas violated the one-person, one-vote guarantee, legislative districts likely would be redrawn in parts of the country with large noncitizen populations, with a noticeable shift toward Republicans.” Naturally, Democrats like things just the way they are, because, they insist, Republicans just don’t want minorities to be represented.

There’s no way of knowing at this point what the Supreme Court will do — at least it was hard to tell from the questioning of the justices. Will it uphold one-person, one-vote, as it has reliably done for decades? Or will it succumb to political expediency and perpetuate the drift away from our bedrock constitutional principles?