The Supreme Court answered this question in 2008 when it upheld Indiana's voter ID law. "Flagrant examples of such fraud … have been documented throughout this Nation's history by respected historians and journalists," the court said, "[and] not only is the risk of voter fraud real but that it could affect the outcome of a close election." But ask voters in Troy, N.Y., Lincoln County, W.Va., and Florida whether voter fraud is a real problem.

Four local officials and party activists were convicted in 2011 of voter fraud in Troy for forging enough absentee ballots to "likely have tipped the city council and county elections" in 2009. Two veteran Democratic political operatives said voter fraud is an accepted way of winning elections. One of them who pled guilty, Anthony DeFiglio, told police that such fraud was a "normal political tactic."

And it is the most vulnerable who are far too often the victims of vote thieves. DeFiglio admitted that the "people who are targeted live in low-income housing … [T]here is a sense that they are a lot less likely to ask any questions."

In March 2012, the county sheriff and clerk in Lincoln County, W.Va., pled guilty to voter fraud. They stuffed enough bogus absentee ballots into ballot boxes to change the outcome of a 2010 Democratic primary election. Was this a one-time incident? Probably not, since the Lincoln County auditor was also found guilty of voter fraud in 2005.

An ongoing review of voter registration rolls in Florida has already found almost 100 confirmed non-citizens registered to vote, half of whom voted in at least one previous election; this in a state that decided the 2000 presidential election by slightly more than 500 votes. During the Bush administration, the Justice Department convicted more than a dozen non-citizens of illegally registering and voting in Florida elections. And the state has thousands more possibly unlawful registrations to investigate.

As the Supreme Court said, vote fraud has been present in our elections throughout our entire history. There are individuals who are willing to take advantage when they see an opportunity to steal an election. We need to be sure that every eligible American is able to vote, but we also need to take the steps necessary to ensure the integrity of our election process.

Hans von Spakovsky is a senior legal fellow at the Heritage Foundation and manager of its Civil Justice Reform Initiative.