JOHNSTOWN — In just two weeks’ time, Mark Critz has risen from virtual unknown to Democratic front-runner in a high-profile congressional race.

That rapid ascendency continued Monday as Democrats selected the Johnstown resident to run in a special election that will determine who fills the unexpired term of the late U.S. Rep. John Murtha.

The decision by the Pennsylvania Democratic Party’s executive board means Critz will face a still-unnamed Republican candidate on the May 18 special ballot.

“I’m honored to have the state committee’s endorsement,” Critz said in a statement issued Monday evening.

“Today, I pledge to all western Pennsylvanians that I’ll work tirelessly to earn their support so that we can come together and get to work bringing jobs to our communities and getting our economy back on track.”

On Thursday, a conference of 134 Republicans from the 12th district will convene in Latrobe to determine who will face Critz in the special election.

Critz’s selection for that ballot came exactly one month after Murtha died from surgical complications at age 77.

Critz, 48, had worked for Murtha for a dozen years, including more than three years as the congressman’s district director. He resigned that post Feb. 22 and announced his candidacy hours later.

He quickly picked up some key endorsements, including backing from Murtha’s widow, Joyce.

On Saturday, Democrats within the nine-county 12th Congressional District recommended Critz for the special ballot.

And on Monday, statewide party leaders followed suit.

“While we look foward to a spirited and exciting race, Democrats across the 12th district should know that Mark Critz will be a phenomenal candidate for this important campaign,” said T.J. Rooney, who chairs the state party.

Rooney also issued a call for party unity.

“Now is the time for Democrats across the district to stand behind Mark in the same committed way that he has stood with them for the last decade,” he said.

The Washington, D.C.-based Democratic Congressional Campaign Committee responded by quickly throwing its support behind Critz.

“Between his record as a public servant and his deep roots in the community, there is no doubt that Mark is exactly the kind of leader the 12th district needs in Congress right now,” said Chris Van Hollen, the campaign committee’s chairman.

Several other Democrats had pursued the special-election nomination: Barbara Hafer of Indiana, a former state treasurer and auditor general; Ed Cernic Jr. of West Taylor Township, who serves as Cambria County controller; and Ryan Bucchianeri of Monongahela, a Navy veteran and businessman.

Of 49 votes cast Monday by the state party’s executive board, Critz received 30 – four more than were needed to secure the nomination.

Hafer came in second with 18, Bucchianeri garnered one and Cernic had zero, party spokesman Patrick McKenna said.

Those who were left out still can campaign for the Democratic nomination in the primary election, also scheduled for

May 18. The primary-ballot winner will move on to November with a chance to win a full two-year term in Murtha’s former House seat.

Cernic said that, because he did not spend time lobbying executive committee members, he was not surprised by Monday’s vote.

While acknowledging that he has “a mountain to climb,” Cernic said he now is focusing on fundraising and connecting with voters for the primary race.

“I’m going to talk about the issues that are near and dear to the people of the 12th Congressional District – jobs, roads and the economy,” Cernic said.

Today is the deadline for those who want to appear on the primary ballot to file nomination petitions in Harrisburg.

According to a list posted on the Pennsylvania Department of State’s Web site, those who had filed their papers as of 4:30 p.m. Monday were Bucchianeri, Critz, Cernic and Republican Tim Burns of Washington County.