With the 2012 U.S. presidential election still 40 days away, voters on Thursday began casting their ballots in Iowa – the first of several so-called battleground states to offer early voting.

“The advantage to the voter is that you can in more good faith turn off all the commotion, you’ve already done your duty and you don’t have to pay attention to all the noise,” said Cary Covington, an associate professor of political science at the University of Iowa. “The advantage to the party is really that a vote cast today is a vote you can’t lose tomorrow.”

President Barack Obama and his Republican challenger, Mitt Romney, begin a series of high profile debates next week.

Covington said campaigns tend to see early voting as a way to push for higher turnout and lock in ballots before any gaffes might take place. That lets them focus dwindling time, attention and resources on those who haven’t voted yet, including the roughly 20 percent of voters who are still undecided.

But early voting traditionally favors Democrats. More than four times as many Democrats as Republicans have requested early voting ballots in Iowa, 119,318 to 24,909 according to the Iowa Secretary of State’s office.

Early voting is allowed in 32 states and Washington, DC, but Iowa is the first of the hotly contested swing states to start its early voting.

Other countries that offer some form of early voting include Australia, Canada, Finland, Germany, New Zealand, Russia, Switzerland and Thailand.

Meanwhile, several states in America are trying to determine how much proof of identification voters must show in order to cast their ballots.

In a Pennsylvania courtroom on Thursday, would-be voters testified about the multiple trips, long lines, misinformation and unexpected expenses they encountered while trying to get the pictures identifications they need to vote under the state’s new Voter ID law that went into effect in March.

Judge Robert Simpson has indicated to lawyers in the case that he may issue an injunction to block the new law from taking effect before the November election. He has until next Tuesday to decide.

Opponents of the law say it could cause problems for as many as 500-thousand voters in Pennsylvania and they argue that many of those impacted would be elderly, women and minority voters.

"In the past two years, more states have passed more laws pushing more voters out of the ballot box than at any time in the past century," said Benjamin Todd Jealous, president and CEO of the National Association for the Advancement of Colored People.  “Strict photo identification requirements disproportionally restrict the ability of people of color to vote and will do nothing to ensure our elections are free and fair.  Sanctioning an intentional block to the ballot box is an affront to the very rights that these laws claim to preserve.”

A recent New York Times/Quinnipiac University/CBS News poll of 1,180 Pennsylvania voters found a vast majority support the law. "While judges and politicians debate Pennsylvania's voter ID measure, voters are solidly in support of the measure, 62 - 35 percent," said Peter A. Brown, assistant director of the Quinnipiac University Polling Institute. “And 99 percent of voters say they believe they have the necessary documents to cast a ballot."

There are 31 states with some form of voter ID laws in place. Three more states have laws that may be enacted before the November election if they clear legal hurdles, according to the National Conference of State Legislatures.