Republican presidential front-runner Mitt Romney has survived the heated GOP nominating contest so far without attracting significant attention to what may become a general election issue: allegations that he committed voter fraud in 2010.

In January 2010 the former Massachusetts governor proudly cast a ballot for Republican Scott Brown in the special election to replace the late Sen. Ted Kennedy. He didn’t own property in the state at the time, and had registered to vote listing his son’s unfinished basement as his residence.

Massachusetts law defines a residence for voter registration purposes as “where a person dwells and which is the center of his domestic, social, and civil life.” Anyone found guilty of committing voter fraud faces up to five years behind bars and a fine of $10,000.

The issue was first raised last year, after long-shot GOP candidate Fred Karger traveled to Romney’s former community of Belmont and interviewed members of his former church — who informed Karger that the Romneys had moved — and their former realtor, who told him, “Oh, they moved to California.”

Additionally, Karger claimed that Ann Romney told him that the couple lived in California.

Karger filed a complaint with the Massachusetts Secretary of State’s Elections Division and the allegations received breathless coverage on “The Rachel Maddow Show.” However, a representative of the Elections Division told The Daily Caller in June 2011 that “the time to bring this up was when he voted.”

Maddow gleefully quoted on her show a Belmont town clerk who told a local publication: “Since he is an active voter, he proves that this is where his residency is” — to which she retorted, “If he has been voting illegally, does the fact that he is voting illegally a lot make it not illegal?”

Despite the initial lack of interest in the issue, if Romney secures the Republican nomination — which appears increasingly likely — supporters of President Barack Obama’s re-election campaign are bound to seek out low-hanging fruit to blemish the former governor’s squeaky-clean public image.

Election law experts contacted by The Daily Caller explained the possible legal justifications for Romney registering to vote at his son’s house, but also noted that significant facts must be established before the presidential candidate can be vindicated of wrongdoing.

Justin Levitt, an election law expert at Loyola Law School, told TheDC that the statute of limitations for prosecuting the alleged crime is likely five years in Massachusetts and five years for federal charges.

Residency for voting purposes “gets tricky in the context of moves,” cautioned Levitt. “One can acquire domicile very, very quickly (if the place where you are is the place you principally call “home”, at the moment), and once acquired, you need to have the intention to firmly call somewhere else “home” (at least for the moment) in order to establish domicile somewhere else.”

For example, said Levitt, “[if] I sell my house, and move in with my family, my family’s house may become my legal ‘home.’ And even if I leave the next week on an extended trip — days or months or years — and even if I have other houses that I’ve purchased elsewhere, if I don’t intend another location to be ‘home,’ but think of myself as still traveling, my family’s house may still be my legal domicile years later, even if I only actually slept there for a week.”

Hans von Spakovsky, a senior legal fellow at The Heritage Foundation and a former member of the Federal Election Commission, explained that “lots of people own second homes in other states but remain registered in their home states.”

“If he intended to maintain his residency at his son’s home and did not take up the accouterments of residency elsewhere, he would still be legal,” said von Spakovsky.

Von Spakovsky, who also worked at the Justice Department on voting issues, noted that one important piece of evidence in establishing Romney’s legal right to vote would be his tax returns. “Election officials will also look at tax returns as crucial evidence in residency disputes,” he said. “Where an individual declares himself to be a resident for tax purposes, thus subjecting himself to applicable state income taxes, is usually decisive on this issue.”

J. Christian Adams, a former voting rights specialist at the Justice Department, told TheDC that voter registration fraud is “very tough” to prosecute. Adams, who has tried similar cases, added that “you need almost something as absurd as the photo to win them.”

“It would all boil down to what the language of the statute is, how broadly [Massachusetts] courts have interpreted it, and what the underlying facts were for Romney,” said Adams. “For example, did he sleep there even once? That would seem to end the inquiry if the statute is interpreted broadly.”

The Romney campaign does not appear intent on clarifying the outstanding questions raised by the voter fraud allegations. Romney spokeswoman Andrea Saul did not respond when TheDC asked if the presidential candidate had spent even one night in his son’s basement, and if he listed his son’s address as his residence on tax documents.

Romney’s street address was redacted on the tax return for 2010, released earlier this year — but it listed Belmont as his town of residence. This does not necessarily clear Romney, however, since he purchased a home in Belmont in June 2010 — approximately 14 months after selling his previous Belmont home in April 2009, and after he had voted using his son’s address.

Massachusetts Gov. Deval Patrick, a Democrat and co-chair of the Obama re-election campaign, has for the moment remained mum about the allegations. His press office declined to comment when contacted by TheDC.

Follow Steven on Twitter