WASHINGTON - It bothers Brian Gronquist that he can vote at his precinct in Andover, just like anywhere else in Minnesota, and not show any photo ID.

"I could be anybody," said the Anoka County businessman.

Increasingly, the act of voting, taken for granted by the majority of nonvoters, is becoming a battleground issue nationwide.

This week, as the presidential campaign picks up momentum, the U.S. Supreme Court will hear an Indiana voter ID case that divides opinion largely along partisan lines -- and puts a pair of Minnesotans in the national spotlight.

One is Rep. Keith Ellison, a Democrat who has helped challenge Indiana's new photo ID requirements as an "unconstitutional poll tax" that discriminates against minorities.

The other is former Minnesota Secretary of State Mary Kiffmeyer, a Republican who has testified in Congress in favor of photo ID requirements, which she says are essential to the integrity of the democratic process.

Not since the 2000 presidential election, which was decided by a few hundred votes in Florida, have the two major parties put so much effort into the mechanics of who can vote and who can't.

"The very closeness of elections ... is making this much more pressing of an issue," said Hamline University Prof. David Schultz, who teaches election law at the University of Minnesota Law School.

Evidence is scanty on both sides of the debate. Ellison and others who oppose photo ID requirements say that real-life cases of "impersonator fraud" -- that is, pretending to be a voter you're not -- are rare or nonexistent.

Similarly, Republicans defending Indiana's new photo ID requirement say the critics have yet to identify anyone who was unable to vote because of the law.

Nevertheless, both sides contend that in a closely divided nation, even a little fraud, or even a few obstacles to voting, could skew election results.

Costs and confidence

In the Indiana case, which will come before the nation's high court on Wednesday, the justices will be asked to rule on a law passed in 2005 by Indiana's Republican-led Legislature requiring voters to have a government-issued photo ID. Voters without ID can cast provisional ballots but must prove their identity within 10 days to a county clerk or board of elections.

Ellison, who filed a "friend of the court" brief in the case last month, argues that Indiana's law is unconstitutional because it effectively imposes a financial obligation to vote. A regular Indiana driver's license costs $21. Although free photo ID cards are available to the indigent, Ellison says they still must incur costs to acquire the documentation needed to get the ID.

To Ellison, who has authored legislation preventing states from requiring photo ID to vote, any costs associated with voting eligibility are tantamount to the Jim Crow-era poll taxes that were banished by the 24th Amendment in 1964.

"It's unquestionable that this scheme creates a real obstacle to voting in federal elections," Ellison argues in his brief, which he submitted along with all 42 other members of the Congressional Black Caucus.

Kiffmeyer, who testified in Congress in November against Ellison's bill, argues that photo ID is about public confidence in the polling system.

As for the presumed burden on the poor and elderly, she said, "I assure you that applying for a photo ID is as easy or easier than getting on welfare or other social services."

Kiffmeyer, as secretary of state, fought a losing legal battle to prevent American Indian tribal IDs from being used for registration in off-reservation elections in Minnesota. The case created a rift not only with Democrats, but with former Minnesota U.S. Attorney Tom Heffelfinger, a Republican appointee who was later targeted for dismissal under President Bush's Justice Department, which supports photo ID laws.

Partisan lenses

The partisan lenses through which these issues are often seen have been clear in the Indiana case. Federal Appeals Court Judge Richard Posner, a Reagan appointee, upheld the Indiana law, writing that "most people who don't have photo ID are low on the economic ladder and thus, if they do vote, are more likely to vote for Democratic than Republican candidates."

Posner's colleague on the U.S. Court of Appeals for the 7th Circuit, Bill Clinton appointee Terence Evans, dissented, calling the photo ID law a "not-too-thinly veiled attempt to discourage election-day turnout by certain folks believed to skew Democratic."

That's how it is seen by Ellison, who bristles at the suggestion that photo ID is not a meaningful burden in today's world. "It's your grandma, it's the lady who lives in the nursing home, it's the people you saw on the rooftops in New Orleans," he said. "This calls on people to imagine that the whole world isn't just like your block."

Ellison and his allies fear that if Indiana's strictest-in-the-nation photo ID law is upheld, other states will follow suit. Several states have imposed new photo ID requirements since the 2000 Florida debacle, including Arizona, Georgia, Michigan and Missouri.

While Democrats tend to view such efforts as a pretext for excluding low-income and minority voters, Republicans say it is Democrats who have bent photo ID into a partisan issue by filtering common-sense antifraud precautions through a political prism.

Gronquist, 54, a self-described conservative and longtime Republican voter in Andover, sees Minnesota's voting requirements as essentially the "honor system." In this fall's Anoka-Hennepin school levy referendum, he said, all he had to do was give his name and tell a poll worker his address.

"We're all assuming everybody is trustworthy and honest," he said.

Kevin Diaz • 202-408-2753