I've read that a Federal law prohibits non-citizens from voting in Federal elections. I'm not a lawyer, but from reading the original Constitution and all the amendments, I don't see anything that empowers Congress to enact such a law. I would have thought that allowing resident aliens to vote would be up to the individual states. What is the Constitutional basis for this law?
TL;DNR: Madison, Hamilton, Justice Harlan & Justice Scalia agree with you. Justice Black does not.
You raise an interesting question. As you point out, the Qualifications Clause, Art I, § 2.1, (those who vote for the House of Representatives “in each State shall have the Qualifications requisite for Electors of the most numerous Branch of the State Legislature”) gives states the power to establish voter qualifications. Yet 18 U.S.C. § 611, passed as part of the Illegal Immigration Reform and Immigrant Responsibility Act of 1996, (the IIRIRA) makes it illegal for most aliens to vote in federal elections. What gives?
First, the IIRIRA is purely symbolic. It literally has no effect on who can vote in the US. For almost a century, every state has prohibited aliens from voting in state elections. Under the Qualifications Clause, this means no aliens can vote in federal elections. (Before WWI, many states allowed aliens to vote.)
Second, some people argue Congress has control over voter qualifications under the "Elections Clause," Art. I, § 4.1, which gives Congress the power to regulate the "Times Places and Manners of holding elections." Like Dale M, these people read, "Manners of holding elections” to include the qualifications for voting.
This reading of the Elections Clause is inconsistent with several of the sources of constitutional authority Americans typically consult, including the text, the intent of the Founder and precedent. All of these support the “Qualifications Clause” reading of the Constitution.
1) Constitutional Text: Reading the Elections Clause as giving Congress control over voter qualifications, renders the Qualifications Clause almost completely meaningless. Yet everyone agrees the Constitution should be read so that all its parts mean something – no part should be rendered superfluous.
2) Intent of the Founders: When the Founders debated voting qualifications, they were clearly worried that politicians would manipulate the electoral rules to favor them. The Founders believed the Qualifications Clause kept both national and state politicians from stacking the electoral deck. First, by giving the power of deciding who could vote to the states, the Clause prevented national politicians from choosing their own electorate. Secondly, by requiring the states to use the same qualifications for voters in state and national elections, the Clause prevented state politicians from manipulating the rules in national elections.
As for the Electoral Clause, in Federalist 60, Hamilton was clear who controlled voter qualifications: “The qualifications of the persons who may choose or be chosen…are unalterable by the [federal] legislature…”
3) Precedent and practice: For most of our history, people acted consistently with Hamilton’s statement. They tolerated a wide variation in who was allowed to vote across states. As noted above, many of those states specifically allowed aliens to vote. (And, starting in 1787 with the passage of the Northwest Ordinance, Congress passed a series of laws allowing aliens to vote in territories.) When Americans did make nationwide changes to voting qualifications, they did so by amending the Constitution.
There are only a handful of Supreme Court decisions involving federal control over voting qualifications. In 1970 the Supreme Court upheld a federal law changing the voting age to 18. The opinion of the Court, written by Justice Black, relied on the Elections Clause to say that Congress had the power to change voting requirements. None of the other Justices shared Black's views on the Elections Clause. Instead, they agreed with Justice Harlan, who said, “nothing” in the Constitution, “lends itself to the view that voting qualifications in federal elections are to be set by Congress.” (These Justices used the Equal Protection Clause as the basis for federal control over voter qualifications.)
Since then, no Justice has followed Justice Black. Instead, they have followed Justice Harlan. For example, in 2013, Justice Scalia, (in an opinion joined by Breyer, Ginsburg, Kagan, Kennedy, Roberts, and Sotomayor) said, “the Elections Clause empowers Congress to regulate how federal elections are held, but not who may vote in them.”
From this evidence, I’d say you were right to be puzzled about the constitutional authority for the IIRIRA. A federal law preventing aliens from voting in federal elections undermines the text of the constitution by rendering the Qualifications Clause superfluous, goes against the clear intent of the Founders, and is inconsistent with 200+ years of history and precedent. It only survives because it has no practical effect on voting in the US.
You asked whether 18 U.S.C. § 611 prohibits aliens from voting for state legislators.
As usual, the answer is: It depends.
In this case, it depends on whether there are candidates for federal office on the ballot. 18 U.S.C. § 611 prohibits aliens from voting in elections that include candidates for a federal office. So if there is no federal candidate on the ballot, this law does not apply.
Even if there is a federal candidate on the ballot, aliens might still be able to vote on state or local candidates or issues. Aliens who are allowed to vote by state or local law, can vote for these candidates or issues in “mixed” elections as long as voting for them:
”is conducted independently of voting for a candidate for such Federal offices, in such a manner that an alien has the opportunity to vote for such other purpose, but not an opportunity to vote for a candidate for any one or more of such Federal offices.”
In English: Aliens can vote as long as they get a ballot that cannot be used to vote for federal candidates.
Of course, this all assumes state law allows aliens to vote. Since no states currently allow aliens to vote, this law has no effect.
You can read the statute, which is atypically short, here:
The Times, Places and Manner of holding Elections for Senators and Representatives, shall be prescribed in each State by the Legislature thereof; but the Congress may at any time by Law make or alter such Regulations, except as to the Places of chusing [sic] Senators.
It’d be this one.