With early voting under way in some states and with Election Day just over two weeks away, the 2008 race is playing out in court as well as at the ballot box.

In Ohio, election officials got a reprieve Friday from the U.S. Supreme Court, which spared them a tedious battle over 200,000 newly registered voters with verification problems. In Michigan, lawyers are battling to ensure that qualified voters, including those who lost their homes to foreclosure, can still cast ballots. In Colorado, tens of thousands of people reportedly have been purged from the voter rolls by officials who, in trying to verify eligibility, relied heavily on a federal database with known problems.

This is the new normal in American elections, experts say. The specter of voter and election fraud is perhaps unavoidable in the era following the hotly disputed 2000 presidential race. Democratic supporters routinely accuse Republicans of voter-suppression efforts. GOP supporters say Democrats inflate voter rolls and ignore evidence of irregularities.

During the final presidential debate last week, John McCain raised the registration issue when he demanded a fuller accounting from Barack Obama of his campaign's ties to ACORN, which has been conducting extensive voter-registration drives. The organization advocates for the poor, who tend to support Democrats. McCain accused ACORN of "maybe perpetrating one of the greatest frauds in voter history in this country, maybe destroying the fabric of democracy."

A day later, senior officials in the U.S. Justice Department confirmed an investigation of ACORN.

On Friday, the Obama campaign asked the Justice Department to have a special prosecutor examine the claims, which it said were reminiscent of unproven voter-fraud cases at the heart of the controversial firing of at least one federal prosecutor in late 2006.

"It's a war on the voters," said Bob Bauer, Obama's general counsel.

"I would say 2008 is typical of recent election experiences but on a much bigger scale," said Doug Chapin, director of electionline.org, which tracks reforms for the Pew Center on the States. He doubts there is widespread ballot fraud and said definitive proof is minuscule.

Complaints will persist

Still, in a nation closely divided along party lines, the complaints won't end anytime soon and likely will continue long after Election Day on Nov. 4.

"Everything we see as indicators is more serious and earlier this time," said Jonah Goldman, a law professor at Georgetown University and director of the National Campaign for Fair Elections, a nonpartisan organization. Some estimates put the number of wrongly disenfranchised voters as high as 6 million, he said.

This isn't how it was supposed to be.

In 2002, Congress passed the Help America Vote Act in response to problems with punch-card ballots in Florida in the 2000 election. The law, passed with overwhelming bipartisan support, ushered in a minimum-level of election standards and greater use of electronic voting machines.

Critics say the law has encouraged states to adopt ID requirements that place a burden on the poor and has enabled election officials to aggressively remove voters from the rolls, even over minor input errors. Both complaints have led to lawsuits across the country, and more are possible after this election.

In April, the Supreme Court upheld an ID law in Indiana, ruling 6-3 that the requirement was not too difficult and that there was little evidence of harm. That ruling cleared the way for other states, including Arizona, to keep similar ID laws in place.

Lawsuits and lingering suspicions may be customary, but fraud isn't, said James Tierney, director of the National State Attorneys General Program at Columbia University.

"These voter-fraud issues are way overemphasized. I think people do the best they can to be fair," said Tierney, who was counsel to Florida's attorney general during the 2000 recount of the presidential election between George W. Bush and Al Gore. "I've been accused of being very, very naive on this, but that is my view."

For months, both parties have waged aggressive campaigns at the local and state levels, accusing their opponents of underhanded tactics.

Last month, the Obama campaign filed a federal lawsuit in Michigan following a report that Republicans planned to challenge the voting eligibility of those who had lost their homes to foreclosure. State GOP officials vehemently deny the claim and have sued for libel the Web site that made the claim.

Across the country in swing states, especially Ohio, the GOP has identified thousands of what it says are dubious registrations - many gathered by ACORN - that included fictitious names, as well as the names of celebrities, ostensibly seeking registration. ACORN officials have said their offices have helped identify the relatively few improper registrations, but state election rules require submitting all registrations, even obviously bogus ones.

The Ohio secretary of state has battled the GOP in her state to prevent challenges to 200,000 disputed registrations. Some include those with typographical errors in the information. Such mistakes are not uncommon. Joe Wurzelbacher, better known as "Joe the Plumber" from the last presidential debate has been registered in Ohio with his name misspelled, as has Debra Bartoshevich, a Wisconsin woman featured in a McCain campaign TV ad who said she had supported Hillary Clinton before backing the Arizona senator.

Rich Coolidge, a spokesman for the Colorado secretary of state, said a criminal case involving ACORN registrations four years ago led to a change in state law. This year, Colorado has had no problems with ACORN, he said.

Ohio embroiled in issues

Ohio has had other voting troubles. The state has been in court with the manufacturer of its electronic voting machines since officials discovered some incorrectly tallied votes in the March primary.

Republicans also complained that Jennifer Brunner, Democratic secretary of state, was being overly technical this summer when she refused to accept applications for absentee ballots from McCain supporters who hadn't checked a box swearing they were truthful. A spokesman for Brunner has said she was following the rules.

Goldman, the Georgetown professor, said the problems in Ohio, coming on the heels of widespread problems under a Republican secretary of state in 2004, are especially troublesome.

"The Ohio Secretary of State's Office seems to be the most hyper-partisan in the country," he said. "Nobody's hands in this are clean."

Several key states, including Colorado, have aggressively removed voters from the official rolls by relying heavily on sometimes-faulty Social Security databases, supposed to be used only as backup, the New York Times reported earlier this month. The effect is that about two voters have been removed for every one who registers, the paper found.

Coolidge insisted last week that Colorado's rolls are accurate and legal.

But in Michigan, a federal judge last week ordered 1,400 people restored to the state's voter rolls because election officials were too quick to delete them. The judge rejected as premature a more ambitious claim that might have immediately restored thousands more.

Voter "caging" is another problem playing out across the country, according to the nonpartisan National Campaign for Fair Elections, which frequently alleges Republican voter-suppression efforts.

Caging is an effort to remove voters from the rolls by aggressive tactics for partisan gain. It dates to the 19th century.

Tierney, the former attorney general's counsel in Florida, agrees that parties have long histories of putting up roadblocks to voting and that technology has made the practice easier.

One popular caging scheme, experts say, involves mass mailings sent to voters at their listed addresses. If the mail is returned as undeliverable to an address, partisan operatives seek to have that voter removed from the rolls.

Such efforts have been documented in minority neighborhoods and often snag the poor, who move more frequently, and college students, whose addresses can change several times within years.

From 2004 to 2006, operatives targeted more than 500,000 voters in caging campaigns in nine states, and at least 77,000 had their eligibility challenged, the National Campaign for Fair Elections found. Goldman, the director, said challenges and other distractions can make voting more time-consuming.

Chapin, of electionline.org, said allegations of voter suppression and widespread voter fraud have something in common: "Neither side has much in the way of empirical evidence."

"The level and volume you have on this issue is a direct result" of 2000, he said. "One of the things that 2000 did was wake people up to the reality that elections don't end on Election Night."