Democratic businessman Scott Murphy clinched victory over Republican state lawmaker Jim Tedisco Friday afternoon in the special House election held March 31 in New York’s 20th Congressional District.

Tedisco conceded the race in a phone call to Murphy, whose razor-thin lead in an election night canvass expanded to hundreds of votes after a protracted counting process that took almost a month to resolve.

Murphy’s win keeps the upstate New York seat, until recently a Republican stronghold, in Democratic Party hands. He will succeed Democrat Kirsten Gillibrand , who was appointed in January to fill the U.S. Senate vacancy created when Democrat Hillary Rodham Clinton was confirmed as President Obama’s secretary of State. Gillibrand had been re-elected last November for a second term in the 20th District seat.

Tedisco, who stepped down as leader of the Republican minority in the state Assembly shortly after the April 7 election, also issued a press release congratulating Murphy.

“Earlier today, I called and congratulated Scott Murphy on a hard-fought contest and wished him well as the next Congressman of the 20th Congressional District,” Tedisco said.

He added, “This was a close campaign every step of the way. Ultimately, it became clear that the numbers were not going our way and that the time had come to step aside and ensure that the next congressman be seated as quickly as possible.”

Tedisco’s concession came with between 700 and 800 challenged absentee ballots yet to be reviewed and possibly counted. But most of those were likely Democratic votes that had been challenged by the Tedisco campaign. With the Republican nominee trailing by 399 votes on Friday, observers agreed it was statistically impossible to make up the difference.

Murphy has been in command since the election officials in the district began counting absentee ballots a week ago, but his victory was not always assured. Murphy led by just 59 votes on election night, when the race was declared too close to call.

The 39-year-old first-time candidate started out the short-turnaround contest as the distinct underdog. The early polls showed him trailing by a wide margin to Tedisco, whose long tenure in the state legislature had given him a significant advantage in name recognition.

Republicans initially framed the unexpected contest in the 20th District — in which their party has a registration advantage of approximately 70,000 voters — as a prime opportunity to reclaim a once reliably Republican seat, and stem the momentum Democrats built with the big gains in the 2006 and 2008 elections. The 20th District was one of those taken over by the Democrats, as Gillibrand unseated Republican Rep. John E. Sweeney in the 2006 election.

House Minority Leader John Boehner of Ohio told the Conservative Political Action Conference in Washington, D.C., in February that the race was “a giant opportunity for us to let America know that America is on our side.” The national party also dumped close to $1 million into the race.

But Murphy’s tireless campaign effort, boosted by national Democrats and labor unions in the final weeks, and his polished performance on the stump helped him close the race to a dead heat by March. Murphy also benefited from Tedisco’s hesitation over Obama’s economic stimulus plan, which the Democrat gave immediate strong support. After being badgered by Murphy’s campaign to take a stand, Tedisco stated that he would have opposed the measure.

Ultimately, both parties portrayed the contest as a referendum on Obama’s policies during the early weeks of his presidency. And Democrats hailed Murphy’s victory Friday as vindication of their agenda.