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In any election year, every vote counts. With stakes every election cycle seemingly higher than the one that preceded it, campaigns, political parties and the third-party groups that support them have a powerful incentive to turn out their voters -- and dissuade those not on their side from even showing up.

Voter suppression is an age-old strategy of manipulating eligibility requirements and limiting access to polls in an effort to shape the electorate.

Antiquated methods of suppressing voter turnout, such as poll taxes, literacy tests and race and gender discrimination, have gone out of vogue. The desire to limit access to the ballot box hasn't, however, so new tactics, both legal and otherwise, have been adapted to the modern election cycle.

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Voter identity laws have a simple aim: ensure the person who casts a ballot is the same registered voter he or she claims to be by requiring that person to provide government-issued photo identification. Verifying the identity of a voter seems like a sensible enough means of preventing election fraud, and is supported by 78 percent of respondents in a recent poll by Rasmussen Report.

Why is this requirement so restrictive? The answer is: Most government-issued photo IDs require a fee. Those that don't cost anything still require documentation, such as a birth certificate or social security card, which themselves may be costly to acquire. Because of these costs, opponents of voter ID requirements have labeled them as poll taxes, a violation of the 24th Amendment.

Furthermore, election experts have insisted and numerous investigations have revealed that voter fraud at polling places in the United States is extremely rare -- a myth propagated and exaggerated for political purposes.

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Recently, Wisconsin Gov. Scott Walker signed into law a bill passed by the state's Republican-controlled legislature to eliminate early voting on nights and weekends in future elections. Walker vetoed an additional provision that would have prevented Milwaukee and other cities from holding early voting for more than 45 hours a week.

Supporters of the law rationalized their decision by claiming the law was meant to promote fairness and uniformity by giving rural and urban voters the same amount of time to cast their ballots and preventing strains on staffing in rural areas needed to support extended hours.

Opponents of these and similar measures passed in states over the past few years contend that reducing early voting opportunities leads to a decrease in overall turnout. As Slate's David Weigel notes, Wisconsin had the second-highest voter turnout rate in the country thanks to its expansive early voting and same-day voter registration policies. Urban polling centers also require additional hours to support the larger number of voters they service relative to their rural counterparts, meaning longer waits in these locations.

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In order to demonstrate eligibility within a particular state or district, voters must provide a residential address before casting a ballot.

Voter caging is the practice of sending a piece of mail to a residence with the intention of uncovering undeliverable addresses. If mail is returned to sender, the voter's right to cast a ballot is challenged, a fact that person might not be aware of until they enter the voting booth.

This tactic was first adopted by the Republican Party in 1981, when 45,000 letters sent to predominantly black neighborhoods were returned as undeliverable. In addition to challenging the eligibility of those voters, the party dispatched off-duty police officers to put up warnings in these neighborhoods about the consequences of violating election law.

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Given all the media coverage surrounding elections and ad dollars spent by candidates, you'd think that even the most apathetic voter would know when to show up at a designated polling station. That turns out not to be the case, however, and there have been numerous attempts and deceiving voters in believing Election Day takes place well after polls officially close.

In 2012, election officials in Maricopa County, Ariz. printed voter registration cards and bookmarks with false information about the date of Election Day. While the English language versions listed the correct date, Nov. 6, the Spanish language print had Nov. 8 written instead. A similar misleading mailer was sent out by the Ottawa County Board of Elections that same year and reached 2,300 registered voters.

Colin Small, enlisted by the Republican Party of Virginia, was caught throwing away completed voter registration forms on the last day for sign-ups in the state. Rockington County Sheriff's Office

Get-out-the-vote drives are intended pull unregistered voters into the electorate, but those former non-voters are only eligible if those registration forms are filed. If the person signing the prospective enrollee up loses the paperwork or doesn't file it, that voter isn't eligible.

Last month, the Los Angeles County Registrar-Recorder/County Clerk's Office began an investigation of how 1,500 completed voter registration forms in a Long Beach city trash can. According to county officials, the forms date back to 2012, and include voters of various party affiliations.

Prior to the 2012 general election, a contractor worker, Colin Small, with a consulting firm, Strategic Allied Consulting, enlisted by the Republican Party of Virginia was caught throwing away completed voter registration forms on the last day for sign-ups in the state. Throwing out completed voter registration forms is a crime, and Small faced 13 counts of election fraud, though those charges were later dropped. The consulting firm itself was investigated for similar crimes, including registering dead people and altering voter paperwork.

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In 46 states, a citizen has the legal right to challenge the voting eligibility of another citizen. Voter challenge laws also vary by state. In Iowa (PDF), for example, eligibility may be challenged if the voter "has been adjudged incompetent to vote," or if the voter is a convicted felon, whereas Michigan (PDF) doesn't allow challenges based on those criteria.

Although election officials have stated that such challenges are rare, according to an investigation undertaken by ABC News in 2012, one county in the swing state of Ohio saw 1,077 citizen challenges in that election cycle alone.

Counting Votes Is a Tricky Business

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Poll watchers may be installed in polling places with the intention of keeping an eye out for election fraud or ineligible voters. What partisan poll watchers seem to be doing across the country, according to various, is intimidating citizens or misinforming them before they reach the voting booth.

An undercover video shot in 2012 of a training session of Republican poll watchers in New Mexico exposed how election observers were taught to provide voters with incorrect information, such as a requirement to show photo identification or a prohibition on interpreters in the voting booth. As reported by Reuters, a similar training course held in Wisconsin for poll watchers also attracted criticism.