At the crux of the closely watched case in the 10th U.S. Circuit Court of Appeals in Denver is whether the federal government or states have ultimate authority to regulate voter registration. Each side contends the U.S. Constitution supports its position.
Monday's arguments come after the U.S. Election Assistance Commission filed an appeal seeking to overturn a federal judge's order that the commission modify a federal form to include special instructions requiring Kansas and Arizona residents to provide citizenship documentation when they register to vote.
The litigation has drawn widespread attention. More than a dozen voting-rights groups have either joined the lawsuit or friend-of-the-court briefs. House Democratic Leader Nancy Pelosi and other top lawmakers urged the appeals court to throw out the lower court's ruling, arguing it would limit the authority of Congress to regulate federal elections and derail its ability to pass legislation protecting the right to vote.
Meanwhile, Georgia and Alabama, which have similar citizenship documentation laws, have filed a friend-of-court brief supporting Kansas and Arizona.
Kansas and Arizona argue the proof-of-citizenship requirement protects the integrity of their elections. But opponents contend the added documentation burdens result in an overall decrease in the number of eligible citizens who will register to vote, undermining the purpose of the 1993 National Voter Registration Act.
Arizona enacted its proof-of-citizenship documentation requirement by voter initiative in 2004, and Alabama, Georgia and Kansas followed with similar laws.
Kansas Secretary of State Kris Kobach has championed his state's law as a way to prevent noncitizens from voting, particularly those living in the U.S. illegally. Critics say incidents of noncitizens registering to vote are extremely rare, and that such Republican-backed laws hurt voter registration efforts and disenfranchise voters from certain groups that tend to vote Democrat, including minorities, college students and older people.
Kobach, a Republican, argues that states have the sovereign right to maintain their voter rolls and that the federal voter registration form should be tailored to the requirements of each state. The states contend the availability of a federal form - which requires only that people attest under penalty of perjury that they are citizens - creates a "massive loophole" in enforcing their voter proof-of-citizenship laws.
In June 2013, the U.S. Supreme Court ruled that states - in that particular case, Arizona - could not refuse to accept the national voter registration form.
But U.S. District Judge Eric Melgren in Kansas in March sided with the states, saying the U.S. Constitution gives states the power to set voter qualifications and Congress has not pre-empted it, even in enacting the voter registration act. Federal election officials appealed, and the 10th Circuit blocked the order until it could hear an expedited appeal before the November elections.
The Election Assistance Commission denied in January Kansas' and Arizona's requests to change the federal form, finding heightened proof-of-citizenship requirements likely would hinder eligible citizens from voting in federal elections.