PHOENIX — A decades-old effort by Congress to make voter registration simple and uniform across the country has run up against a new era’s anti-immigration politics. So on Tuesday, when Arizona’s polls open for primaries for governor, attorney general and a host of other state and local positions as well as for Congress, some voters will be permitted to vote only in the race for Congress.
As voter registration drives intensify in the coming weeks, the list of voters on the “federal only” rolls for the November general elections could reach the thousands. These are voters who could not produce the paper proof of citizenship that Arizona demands for voting in state elections.
The unusual division of voters into two tiers imposed by Arizona and Kansas, and being considered in Georgia, Alabama and elsewhere, is at the center of a constitutional showdown and, as Richard L. Hasen, an elections expert at the University of California, Irvine, put it, “part of a larger partisan struggle over the control of elections.”
The issues will be argued Monday before a panel of the United States Court of Appeals for the 10th Circuit in Denver. This year, the circuit court temporarily blocked a lower court decision that would have forced federal officials to include the state’s proof of citizenship requirements on registration forms used in Arizona and Kansas.
Apart from the legal principles at stake, groups working to sign up voters say the document requirements will most heavily affect minorities, the poor, older adults and also college students who move into the state, effectively disenfranchising some.
“These restrictive registration laws only add to the barriers facing Latino voters,” said Raquel Terán, the Arizona director of Mi Familia Vota, a national group promoting Hispanic political participation. Federal election officials and other experts say that illegal voting by noncitizens is rare and inconsequential.
The documentary requirements imposed by Arizona and Kansas are at odds with a 1993 federal law that requires potential voters in federal elections simply to swear on penalty of perjury, and perhaps deportation, that they are citizens. Federal registration forms, accepted by nearly all the states alongside their own forms, do not ask for supporting paperwork like birth certificates, which some find hard to obtain.
Arizona’s attorney general, Tom Horne, a Republican, sees the dispute over voter certification as a winning issue as he campaigns for re-election.
“People are very emotional about illegals voting and diluting their own votes,” Mr. Horne said in an interview.
Mr. Horne, who is battling allegations of campaign finance and other ethics violations, is known for his hard-line views on immigration. In speeches and a new television ad, he boasts that he “fought voter fraud” by personally defending Arizona’s proof-of-citizenship rules in court. Just how many voters will be frozen out of local and state elections is unclear. Here in Maricopa County, which accounts for 60 percent of Arizona’s population, officials said that as of last week, 811 voters were on the federal-only list, but only 303 of them were considered “active voters.”
Based on past experience, intensified voter drives in coming weeks will result in a surge of new registrations, including many from people who do not have birth certificates or other documents at hand, said Sam Wercinski, executive director of the Arizona Advocacy Network, a liberal group promoting “electoral justice.”
Even if some of them eventually muster the needed proof, he said, if they do not provide it before the Oct. 6 deadline, “they will be disenfranchised for the November election.”
Beyond that, no one has statewide data on those who consider registering but are rejected or deterred from applying. For some, the requirements can be cumbersome: Women who married and changed their names, for example, must show not only a birth certificate but also a marriage certificate. An older resident who moved here after decades of voting in another state may have trouble obtaining a birth certificate, or strain to pay the fee to obtain it.
In Kansas, while the federal-only rolls are small, about 19,000 applicants have been placed on a “suspense list” because their state forms are incomplete, in some cases because they did not provide the newly required proof of citizenship, said Dolores Furtado, president of the League of Women Voters of Kansas.
Registration drives here have been complicated by the need to offer different forms. Most applicants fill out the state form if they have the required proof, which for many here is an Arizona driver’s license first obtained since 1996, when citizenship status was registered on licenses. Others use the federal form, ending up on the federal-only roll.
College students arriving from other states who want to vote in Arizona are often affected since they are unlikely to have birth certificates or other proof of citizenship with them, although they can change their status in the future if they obtain them.
On the eve of the fall semester at Arizona State University last week, numerous incoming students who registered to vote were astonished to learn that they had truncated rights.
“I’m going to be here for four years, perhaps longer, and I want to make my voice heard on local issues that will affect me,” said Sam Leffler, a freshman from Denver as he expressed frustration that he would be limited to voting in federal elections for now.
Republican officials like Mr. Horne and Kris W. Kobach, the Kansas secretary of state, insist that fraudulent registration is a significant threat, citing anecdotal reports and sporadic prosecutions.
But the federal Election Assistance Commission, when in January it again turned down the Arizona and Kansas requests to alter the federal form, concluded that the number of confirmed fraud cases is minute and “is not cause to conclude that additional proof of citizenship must be required.”
Most elections scholars say that the simpler federal requirement of a sworn statement has worked well.
“If you’re not a citizen, why would you jeopardize your status and even face deportation for something that is unlikely to make any difference?” said Michael P. McDonald, a political scientist at the University of Florida.
The clash over voter requirements is unlikely to be resolved by the appeals court.
In 2004, amid rising concern about illegal immigration, Arizona voters mandated that newly registering voters show proof of citizenship, and the state has engaged in legal skirmishes with federal officials ever since. Kansas adopted a similar requirement in 2011.
The Constitution gives states primary, but not total, control over voter requirements. In a series of federal court battles, including a round in the Supreme Court, Arizona and Kansas have sought to force the federal elections agency to add documentation requirements to the federal form in their states.
“The big lurking question is: Can states undermine the power of Congress to set minimum standards for federal elections?” said Wendy R. Weiser, a lawyer with the Brennan Center for Justice at New York University, which has represented the League of Women Voters in the case.
If the states win in court, the federal forms will be revised in those states, and two-tier voting will end — with some potential voters unable to register. If the federal elections agency and civic groups prevail, the federal form will remain as it is.
But the states have pledged, in that case, to maintain dual registries even in the face of further court challenges.
“The federal government has no right to tell us what to do in our state elections,” said Mr. Horne, the embattled attorney general.