Republicans are bragging that they’ve retaken the lead among registered voters in San Diego County, the second largest county in California. At the beginning of last month, Republicans trailed Democrats by 4,850 voters. Now, they lead by 891.

Although the county has leaned Republican since the 1980s, Democrats claimed the lead in October 2008, during the “Obama surge,” says Ron Nehring, chairman of the California Republican Party. He tells National Review Online that the victory is due in part to a statewide campaign to register more Republicans, which the party started in October 2009. “Over the last 11 months, we registered over 220,000 Republicans in the state, and over 26,000 in San Diego,” he says.

But Jess Durfee, chairman of San Diego County Democratic Party, says the GOP is buying voters. “They’ve spent literally tens of thousands on a paid registration program looking under every rock for a person to register,” says Durfee. “We depend on a volunteer program.” He also says that the Republican margin increased because the registrar of voters purged inactive Democrats — e.g. students — from the rolls. “Voters who request absentee ballots that are sent to homes and returned get purged. A lot of people we registered in 2008 were students. Many of the students, I’m guessing, got purged because they were somewhere else in the summer.”

No one knows which towns in the county gave Republicans their new members. Traditionally, the Republican areas are the north and east; the Democratic areas are the city of San Diego and the south.

Still, San Diego may be starting a trend. Republican registration is rising in Fresno County, where there are now 159,597 Republicans to 161,447 Democrats.

And these are places where Democrats should be doing well. “When [the Democrats] took [San Diego County] in October 2008, they were crowing that demographic changes would ensure their control of the county,” says Nehring. “That only lasted less than two years, and here we are. This is a coastal county, a partially urban and suburban county, and it fits the typecast of what the Democrats claim favors them.”

Or did favor them.