Republicans are considering taking legal action against Sen. Mary Landrieu (D-La.) to question whether she is a resident of Louisiana, arguing that her $2.5 million home just four blocks from the U.S. Capitol is her primary residence.

Raising questions about a candidate's residency is an age-old political tactic used by incumbents and challengers alike to question whether an opponent is qualified for the job or sufficiently focused on home state concerns.

Democrats responded to the accusations against Landrieu, reported Thursday by The Washington Post, by noting that two GOP Senate candidates -- Tom Cotton in Arkansas and Dan Sullivan in Alaska -- have also faced questions about their home addresses. Cotton doesn't own property in Arkansas and has spent most of his time since high school outside the state (partly because of his military service). As for Sullivan, he was born in Ohio and has strong family ties there. He's lived in Alaska in recent years, but Democrats have raised questions about his residency based on applications for fishing licenses.

But several recent cases demonstrate that residency questions don't always matter. Here’s a quick review of when a candidate residency played a prominent role -- and how it panned out:


Sen. Richard Lugar (R-Ind.): The Hoosier State’s former senior senator lost reelection in 2012 after news reports revealed that he stayed in hotels whenever he visited Indiana and kept his primary home in Virginia. Making matters worse, Lugar didn't seem to heed the warnings of GOP strategists, who had warned him that he might lose if he didn't aggressively tackle the appearance of being disconnected from his home state. Lugar didn't think he had to worry -- he'd won reelection with more than 67 percent of the vote since 1982. But ultimately, the residency issue contributed to his downfall. He was defeated in a GOP primary by Richard Mourdock, who went on to lose to Sen. Joe Donnelly (D).


Sen. Rick Santorum (R-Pa.): Pennsylvania’s then-junior senator owned a two-bedroom home in a Pittsburgh neighborhood and claimed that he and his large young family lived there. But he also kept a large home in Northern Virginia, much closer to the U.S. Capitol. When the Pittsburgh Post-Gazette sent letters to candidates to gather information for a voters guide, the Postal Service sent back the mailing stamped "Not Deliverable As Addressed -- Unable To Forward." That was all the proof that the newspaper -- and many voters -- needed. While Santorum maintained legal residency in the commonwealth, he and his family were living hundreds of miles away. The flap contributed -- but didn't outright cause -- Santorum's loss in a year when several Republicans were turned out due to their ties to George W. Bush, who was deeply unpopular due to the war in Iraq and his response to Hurricane Katrina.


Sen. Edward Markey (D-Mass.): The longtime House lawmaker claims his childhood home outside Boston as his voting address, but lives most of the time in the D.C. suburb of Chevy Chase. Part of the reason he has spent so much time in and around the Beltway is that his wife, Susan Blumenthal, is a longtime health-care consultant and former Clinton administration official who had no personal connection to Massachusetts. In the race to succeed former Sen. John F. Kerry (D-Mass.) last year, Republicans tried to cast Markey as out of touch with Massachusetts voters and a D.C. creature who rarely bothered to come home. In response, Markey began making more frequent trips to the Bay State and the accusations never stuck. He still lives in Chevy Chase, and is frequently spotted in the neighborhood attending church or shopping in supermarkets.

Sen. Hillary Rodham Clinton (D-N.Y.): Campaigning in 2000 to succeed retiring Sen. Daniel Patrick Moynihan (D-N.Y.), the first lady was almost immediately labeled a “carpetbagger,” who was taking advantage of Empire State residency rules that only require that a Senate candidate be a legal state resident by Election Day in order to qualify. But it didn’t work. Clinton was helped in part by a former occupant of her seat, Robert F. Kennedy, who also took advantage of the residency rules and won the seat in 1964 with little concern for his lack of New York roots.

Mitt Romney (R): While running for governor of Massachusetts in 2002, Romney faced questions about his residency status after The Boston Globe reported he had saved $54,000 in property taxes by claiming a Utah home as his primary residence. Romney -- whose aides blamed the tax break on a clerical error -- weathered the storm to become governor and went on to wage two unsuccessful presidential campaigns.


Sen. Pat Roberts (R-Kan.): He is registered to vote at the address of Dodge City supporters he pays rent to and stays with when he is in town, according to a blockbuster New York Times scoop from earlier this year. He also owns a home in Dodge City, but he rents it out and lives with his wife in Northern Virginia. The revelations shocked the political community: How could another longtime Republican senator make a Lugar-like mistake? But Roberts immediately pushed back. A campaign statement said that Roberts "pays Kansas state tax and property tax. His three children attended college in Kansas. He is a Kansan. He lives in Dodge City by every measure of residency." It took much longer for Lugar to respond in kind. The accusations didn't help Roberts's primary challenger, Milton Wolf, but they might yet be a factor in November. Polls suggest that Roberts is locked in a tight three-way general election fight, though Republicans have won every U.S. Senate race in Kansas since 1932.

Former Sen. Scott Brown: The former Massachusetts senator is now running to unseat Sen. Jeanne Shaheen (D-N.H.) in neighboring New Hampshire. Democrats immediately labeled him a carpetbagger (see Clinton, Hillary, above) and noted that Shaheen has gold-plated Granite State credentials as a former governor. But a growing percentage of New Hampshire residents moved north from Massachusetts and Brown remains in a competitive race with Shaheen. Will Brown's genuine Bay State appeal work up north? Stay tuned.