Republican David Jolly has won the special election in Florida’s 13th Congressional District, defeating Democratic candidate Alex Sink and Libertarian Lucas Overby.

With all precincts reporting, Jolly holds a lead of about 3,400 votes, capturing 48.43% of the vote to 46.56% for Sink and 4.83% for Overby. Sink has conceded the race.

Jolly’s victory is a minor upset for the GOP. Sink held an advantage among early voters and a slim lead in pre-election polls. A handful of unnamed Republican officials had even taken to the press to trash Jolly’s campaign ahead of an expected loss. But when the polls closed, Jolly’s advantage with election-day voters quickly sealed Sink’s fate.

The race was a proxy war for Democrats and Republicans as they test out new midterm election strategies. The Pinellas County district, left vacant by the death of longtime Republican Congressman C.W. Bill Young, went 50-49 for President Obama in 2012, making it a rare swing seat in the overwhelmingly polarized and gerrymandered House.

Sink, the Democrats’ 2010 gubernatorial nominee, outraised Jolly by a wide margin, but the bulk of cash in the race didn’t come from the campaigns themselves. Outside spending, which included the national parties and a variety of liberal and conservative advocacy groups, accounted for $8.8 million of the $12 million overall spent on the contest.

Close video GOP candidate wins Florida special election Republican David Jolly won the first congressional race of 2014, beating Democratic challenger Alex Sink in a special election in Florida. Republican David Jolly won the first congressional race of 2014, beating Democratic challenger Alex Sink in a special election in Florida. share tweet email Embed

Republican and conservative groups went after Sink for supporting portions of Obamacare, running ads decrying its cuts to Medicare Advantage payments and highlighting canceled insurance plans that didn’t meet the law’s standards. Democratic groups attacked Jolly for his career as a lobbyist, taking special aim at his work with a client who favored privatizing Social Security. They also targeted Jolly’s pro-life stance, which connects to broader Democratic claims of a “War on Women” by GOP candidates.

Individual special elections don’t usually have much predictive effect when it comes to November elections. Democrats, who have a strong record in recent years on this front, won hotly contested races in 2009 and 2010 ahead of a disastrous election cycle in which they lost the House.

But in the short term, it’s an energizing pickup for Republicans, who have long boasted that their focus on Obamacare will lead to gains in the House and a majority in the Senate.

“Tonight, one of Nancy Pelosi’s most prized candidates was ultimately brought down because of her unwavering support for ObamaCare, and that should be a loud warning for other Democrats running coast to coast,” Congressman Greg Walden, chairman of the National Republican Congressional Committee, said in a statement.

Looking forward, Republicans are hoping the electorate will look more like the 2010 midterms, when young and minority voter participation dropped off, than 2012, where Obama’s presence on the ticket boosted their turnout. Florida’s 13th District is disproportionately elderly and white, a demographic that’s buffeted the GOP in recent years and tends to vote more reliably in midterm races. Republicans will likely be encouraged by Jolly’s election that, even without a strong candidate, they might pick up seats with the same playbook in 2014.

Steve Israel, chair of the Democratic Congressional Campaign Committee, argued in a statement that Jolly “underperformed” given that the seat had been held by a Republican for decades. He added that Democrats will try again to capture the seat in November, “when the electorate is far less heavily tilted toward Republicans.”

Regardless of its bellwether status, the race is a good a preview of the types of campaign messages voters can expect to see in districts around the country. With outside spending surging upwards, odds are good that your TV programming will look like Florida’s 13th soon enough.