Is a federal ban on alien voting unconstitutional?

As a part of the Illegal Immigration Reform and Immigrant Responsibility Act of 1996, 18 U.S.C. 611(a) reads, "It shall be unlawful for any alien to vote in any election held solely or in part for the purpose of electing a candidate for the office of President, Vice President, Presidential elector, Member of the Senate, Member of the House of Representatives, Delegate from the District of Columbia, or Resident Commissioner," unless they are voting for non-federal officials on a different ballot.

In Inter Tribal, the Court found that the power to prescribe and enforce the qualifications of voters resides in the states, and that the federal government has no role (at least under the Elections Clause).

So what happens to this provision? There has been some speculation that the Court's opinion about the state's power over voter qualifications, and Congress's lack thereof, would be limited to the context of the Elections Clause, and that other sources of power (e.g., the Reconstruction Amendments) might offer an alternative basis for Congress to regulate voter qualifications.

And after the opinion, there was much concern, from commentators concerned about the impact if Congress may one day want to enfranchise felons (a prospect I find a highly dubious political likelihood), to a question about the sustainability of the Uniformed and Overseas Citizens Absentee Voting Act.

But these concerns arise from areas where Congress has, or may, extend (or protect) the right to vote to certain groups when a state may disenfranchise them. The provision of IIRIRA does just the opposite--it disenfranchises a group that a state may want to enfranchise.

Granted, all fifty states at the moment disenfranchise noncitizens in statewide elections, but some allow noncitizen voting in local elections, and some localities have embraced noncitizen voting. 

If, however, an individual is prosecuted or deported under this provision, would Inter Tribal suggest the law is unconstitutional? 

I suppose one could make the argument that Congress's broad power over immigration would be the source of that power. But I do think it's telling that Congress restricted itself to regulating only federal elections. It is perhaps a concession that Congress believed it was acting within its more limited power to regulate elections, not in the broader area of immigration.

And if that's the case, I wonder if the judicial "conservatives" (more inclined to empower states to determine voter qualifications) and the judicial "liberals" (more inclined to remove rules restricting the right to vote) would join an opinion in a future case to strike down this provision. It's worth considering in the years ahead.

UPDATE 2020: A lot has happened since this little blog post! See this 2017 piece in the Loyola Law Review for an extended critique on the ban. Others have urged me to reconsider the scope of Congress’s immigration power, which they argue can extend to regulate the activities of non-citizens in the United States even in relation to voting. Still others have suggested that the federal government could enforce state-related voting rules in federal elections, akin to its power under the Enforcement Acts. Regardless, I came back to lightly edit this post and update it given a number of federal criminal charges filed under Section 611(a) in North Carolina.