Republican Senate candidate Dan Sullivan received a tax break in Maryland that aids Senator Mark Begich (D., Alaska) in arguing that Sullivan isn’t a real Alaskan.

“Maryland authorities say he doesn’t have to repay about $5,000 in homestead tax credits he received from 2006 to 2008, for a home he owned in Bethesda,” Alaska Public Radio notes. “Only owners claiming a home as their principal residence are entitled to the credits.”

The Sullivans lived in Maryland when he worked in the Bush administration.

The state Democratic Party pounced on the news. “It’s clear at this point he’s been dishonest on the campaign trail, because his official declaration of candidacy says he’s a 17-year resident of Alaska, and he and his spokesman have said that he’s been a resident of Alaska since 1997,” spokesman Zack Fields said.

“Mark Begich has made it abundantly clear he is willing to say or do anything to shamefully distort Dan’s record, and this time was clearly no different,” the Sullivan campaign said in a statement. “Begich’s campaign has been one desperate attempt after another to distract from his failed record of telling Alaskans one thing, and then turning around and voting with Barack Obama 97% of the time.”

Democrats have attacked Sullivan on this issue at every opportunity. A super PAC attack ad focused on abortion and birth control suggested that Sullivan would have Democratic views on those issues “if he was actually from Alaska.”

Sullivan emphasizes his Alaska connections on his website. “I’ve dedicated my life to serving Alaska and America,” he says. “I’ve served on active duty and in the reserves in the U.S. Marine Corps for 20 years as an infantry officer. As Alaska’s Attorney General and Commissioner of the Department of Natural Resources, I focused on protecting Alaskans, promoting energy security and economic opportunity, and fighting against the Obama Administration’s overreach.”