U.S. Rep. Frank R. Wolf’s announcement in December that he would not seek reelection to an 18th term in Congress came as a surprise to both Republicans and Democrats.

Wolf’s retirement notice instantly set off a feeding frenzy among politicians maneuvering to gain the Northern Virginia Congressional seat.

The 74-year-old Republican held the seat for more than three decades. But Democrats now see a prize pickup opportunity for this year’s midterm elections, and potential candidates have rapidly dropped in and out of the race as political pundits question how red the district will remain.

Democrat John Foust, a Fairfax County Supervisor from McLean, announced he would challenge the incumbent a week before Wolf’s retirement news.

Del. Barbara Comstock (R-34), a McLean attorney and Wolf’s former senior aide, emerged as the one to watch when she announced her candidacy in January. Like Foust, Comstock is a formidable fundraiser and she quickly received the endorsement of many party officials, including presidential hopeful Mitt Romney, for whom she worked in the 2012 campaign.

DEMOCRATIC STRATEGISTS considered Foust to be one of Wolf’s most challenging opponents in years, and Foust quickly racked up a slew of endorsements from more than 50 former and current elected officials, including Lt. Gov. Ralph Northam and U.S. Rep. Jim Moran (D-8). Moran later announced he would not seek reelection. Foust’s momentum had a rainmaking impact on donors. In late January, Foust reported raising more than $217,000, with nearly that amount — $210,000 — reported as cash on hand.

"This is another clear sign that our message of bringing problem solving, bipartisan leadership back to Congress is resonating with Northern Virginia residents," Foust said in a statement about his successful fundraising.

"We had fewer than 20 days to do three months of work, but residents sent a clear message that they’re tired of the gridlock and finger-pointing in Washington and are ready for our brand of commonsense leadership."

"My money is on John Foust," said Sharon Bulova, chairman of the Fairfax County Board of Supervisors in an interview Sunday. "His constituent service is second to none and he has really delivered for his Dranesville constituents. Republicans and Democrats alike love him."

In less than a month, three other Democrats currently join Foust in vying for the seat: Fairfax lawyer Richard Bolger, Leesburg architect Sam Kubba and Iraq War veteran David Wroblewski. Several others might still consider a run.

ON THE REPUBLICAN SIDE, speculation about who would enter the race ran the gamut from the obvious to the absurd. Tareq Salahi, a write-in candidate for last year’s governor’s race, remains in the race. A vintner and television personality, Salahi gained national attention when he and his ex-wife crashed a White House state dinner in 2009.

When announcing her candidacy, Comstock said: "I have a demonstrated record of winning important legislative victories for Northern Virginians as well as winning hard fought, principled elections."

Comstock’s mainstream GOP platform includes "repealing and replacing Obamacare," as well as promoting policies for a healthier economy and "fighting to protect our national security and dedicated military."

"I will be a tireless advocate for one of the most vibrant and diverse communities in the Commonwealth and I will demand and work hard for common sense results," she said in a news release. "I am running for Congress because I believe my strong record as a common sense conservative leader is what is needed in Congress. I know how to effectively fight for Northern Virginia's hard working taxpayers having first learned from Congressman Wolf, working in his congressional office."

Comstock is currently facing seven declared candidates for her party’s nomination, including a challenge from Virginia Del. Bob Marshall, who entered the crowded Republican primary field last week.

In a news release announcing his candidacy, Marshall, who has represented parts of Prince William and Loudoun counties in the General Assembly for more than 20 years, vowed to vote no to any tax increases, and said he would "be on the front lines to defund and dismantle Obamacare. "

Marshall also said in his announcement that he would oppose "the creation or maintenance of a police surveillance state to spy on us," and oppose the "executive assault" on congressional powers. He told reporters he believes his candidacy will appeal to the conservative party activists.

Earlier this month another Republican, Rob Wasinger of Fairfax Station, announced his candidacy, citing 20 years of experience of working for prominent conservative lawmakers on Capitol Hill.

Potential candidates have until March 27 to file the necessary paperwork for a run.