Voter ID laws have received plenty of attention recently, but they're not the only controversial changes to election rules this year. Some states have made changes that critics say could impact individuals' ability to vote. Here are four.

Ohio won't count provisional ballots mistakenly cast in the wrong precinct.

Four years ago in Ohio, there were 200,000 provisional ballots cast among a total 5.7 million votes. This was the most among any state other than California. (Federal law requires states to use provisional ballots when a voter's eligibility is in question or if their registration doesn't reflect a new name or address.)

But Ohio requires county election boards to reject provisional ballots if the ballot doesn't correspond to the voter's assigned precinct — even if it was the poll worker's mistake. (A few other states have similar rules, but Ohio is fighting a lawsuit right now to preserve its approach.)

Such errors are bound to happen since 80 percent of Ohio's polling stations cover multiple precincts. In 2008, Ohio elections officials discarded 14,000 provisional ballots for this very reason. That number accounted for one-third of the total rejected provisional ballots that year.

In June, a group of labor organizations and advocacy groups sued Ohio to block enforcement of this requirement, arguing it could disenfranchise thousands of voters.

Ohio officials have argued the law is justified by the state's interest in "running elections fairly and efficiently."

"The argument is sometimes made that if states are required to count these ballots, more people would deliberately go and vote in the wrong precinct," said Wendy R. Weiser, director of the Democracy Program at the Brennan Center for Justice.

During oral arguments before a federal judge earlier this year, a lawyer for Ohio hinted at such a scenario when he challenged the strength of the plaintiffs' evidence. "Something else is going on that may not be poll-worker error," he said, as noted in a footnote to the judge's ruling.

In August, a federal judge ruled against Ohio's approach. The state's interest in fair and efficient elections, wrote U.S. District Judge Algenon Marbley for the Southern District of Ohio, "falls short of what is required to justify its inevitable disenfranchisement of thousands of qualified voters in the November 2012 election."

Ohio has appealed the decision, arguing that the rule helps with "counting only valid, legal ballots, in running a smooth election, and in minimizing post-election litigation." Allowing such provisional ballots to count, the state further argued, would make it "more difficult for elections officials to monitor and keep up with the voting process."

The Sixth Circuit Court of Appeals heard arguments in the case early last week and is expected to issue a decision soon.

Ohio tried to shorten its early voting period — until a federal court ruled otherwise.

Ohio used to permit in-person early voting for registered voters in the three days prior to Election Day. (More than 30 other states have similar early voting options, mostly for those who can't make it on Election Day.) But last year, the Ohio General Assembly limited the window. Early voting, which began Oct. 2, was scheduled to end 6 p.m. the Friday before Election Day. (Members of the military and overseas voters were exempt from the narrowed time frame.)

Democrats have been proponents of early voting: An estimated 93,000 Ohioans voted early in 2008. A subsequent University of Akron study concluded that early voters were "more likely to be strong Democrats than election-day voters" — including women, older voters and lower-income individuals.

In defending the law, Ohio elections officials argued that administering early voting the weekend before Election Day for all registered voters would interfere with counties' Election Day preparation, and that military voters have a unique need for being exempt.

In July, Obama for America, the Democratic National Committee and the Ohio Democratic Party asked a federal court to block the new rule, arguing that "tens of thousands of citizens who would have otherwise exercised their right to vote during this time period, including Plaintiffs' members and supporters, may not be able to participate in future elections at all."

In August, U.S. District Judge Peter C. Economus in Ohio agreed to block the law, writing that creating two separate early voting deadlines would place more value on one person's vote over another's. On Friday, the U.S. Court of Appeals for the Sixth Circuit affirmed this decision. County elections officials, as in 2008, will still have discretion over whether to open up early voting to all.

Ohio Secretary of State Jon Husted said he plans to appeal the decision to the U.S. Supreme Court.

Iowa has hired a criminal agent to investigate voter fraud allegations.

In July, the Associated Press reported that Iowa signed a two-year $280,000 contract with an investigator from the state Division of Criminal Investigation to handle suspected cases of voter fraud. The agent's duties, according to the AP, are "subpoenaing voting records, checking their citizenship status, and interviewing suspects as he builds cases."

Iowa's Secretary of State Matt Schultz has identified more than 1,000 names of potential non-citizens to investigate. (Schultz has not responded to requests for comment.)

The first few cases haven't exactly revealed massive fraud: Two Canadian citizens arrested and charged with felony election misconduct for voting in 2010 and 2011 said they mistakenly believed they could vote in non-presidential elections as legal residents. A third person arrested was a Mexico native whose U.S. citizenship was challenged by the state.

As we've noted before, studies show that voter fraud is actually quite rare.

Other measures taken by Schultz's office — such as allowing anonymous voter fraud online complaints and pursuing non-citizen purging — has prompted legal action from the ACLU.

Texas has notified (living) voters that they are "potentially deceased."

Last year, the Texas Legislature passed a bill to ensure dead people were kept off its voter rolls. States have long been required to maintain clean voter rolls, so such updating isn't new.

But Texas went further, giving the secretary of state authority to conduct voter roll purges using relatively loose criteria like shared names and birthdate.

The result is that live voters have received notice that if they don't respond within 30 days, they're assumed dead and will be removed from the voter rolls.

The state's largest voting district, Harris County, has sent such letters to about 4,000 "potentially deceased" voters.

"Several hundred responded that said, 'Yeah, I'm still alive,'" said Fred King, communications manager for the Harris County Voter Registrar and Tax Office.

Election experts say that's not surprising. "The problem is that there is a much higher incidence of sharing names and birth dates than people realize," said David Becker, director of election initiatives at the Pew Center on the States.

After a lawsuit from four quite live voters, Texas agreed last week to roll back the purge. "Potentially deceased" voters will still be flagged, but will only be removed from the rolls if there's a hard match. (Secretary of State Hope Andrade has said that's just a technical change.)

The purge had also been criticized for being started just months before the election. The new law mandating the controversial letters took effect a year ago in September 2011. Texas didn't start the purge until just this June.

"Most states recognize it's good policy to do this throughout the year rather than right before an election," says Becker of the Pew Center on the States.

So what explains Texas' decision to wait?

"We wanted to run the process with enough time between elections," Texas Secretary of State spokesman Richard Parsons told ProPublica. "Unfortunately repeated election delays, shifting deadlines and uncertainty all caused by ongoing redistricting litigation did not allow for this process to move forward any sooner."

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