Former Virginia Congressman Virgil Goode has turned in 20,500 signatures in his quest to make the presidential ballot in his home state, an effort that could potentially derail Republican Mitt Romney's presidential aspirations in a critical battleground state.

At least 10,000 valid signatures are due Friday at noon to the State Board of Elections to make the ballot. Election officials will next send the petitions to local registrars to verify the signatures.

Goode said he is optimistic he'll qualify, but just this week, the Constitution Party was forced to back out of the presidential race in Pennsylvania after the Republican Party challenged the validity of its petitions. There, Goode and his running mate, Pennsylvania native James Clymer, amassed 35,000 signatures -- 15,000 more than needed -- but the GOP raised issues with signatures from unregistered voters and names that did not match addresses.

"The Republicans have challenged wherever they can, wherever they feel like they can do it successfully," Goode said.

Republicans and Romney have the most to lose by Goode's presence in the race, particularly in Virginia. Goode remains popular in conservative circles in southern Virginia, an area where he served as a pro-gun, pro-life Democrat in the state Senate, and in Congress as a Democrat, Republican and independent between 1997 and 2009.

A Public Policy Polling survey released this summer showed Goode pulling in 9 percent of the vote in the presidential race, stealing support chiefly from Romney. It's a fact not lost on Democrats, who hope Goode can help President Obama win one of the most important swing states on this fall's electoral map.

"Certainly, the Democratic Party has had no communication with Goode, but it wouldn't be surprising if a bunch of us are rooting him to make the ballot," a Northern Virginia Democratic Party leader said. "We've had some brief discussions, a little bit of cackling that it creates one more problem for [Romney]. We'll remind people ever so casually that [Goode's] on there."

A spokesman for the State Board of Elections said the Libertarian Party has already handed in petitions, and the Green Party is expected to Friday. In 2008, four third-party candidates appeared on the ballot.

Goode said Obama and Romney would both gut Medicare, and his tough stance on immigration, including a moratorium on green cards until unemployment is below 5 percent, has attracted voters disenfranchised by the traditional parties.

"We really don't have much of a choice between Obama and Romney," Goode said. "Neither one of them are for Medicare or taking the steps that's needed for jobs in America. It's a very distinct difference between Romney and Obama and myself."