With Conservative Party candidate Doug Hoffman running neck and neck with the Democrat in Tuesday’s special election in New York, some other disaffected Republicans are seeing the third-party route as more viable.

And it could hurt the Republicans in those races.

In Virginia’s 5th district, state Sen. Robert Hurt’s entry into the GOP primary has spurred little-known candidate Bradley Rees to switch to the Virginia Conservative Party. And in Ohio, another GOP primary contender said this week that he’ll run as a Constitution Party candidate.

Both will go at the GOP nominees from their right flanks and try to expose some unhappiness in conservative ranks. They might not be as well-funded as Hoffman or be filling quite as big a vacuum as the one left by Republican Dede Scozzafava’s left-leaning politcs, but they could steal valuable votes.

Rees isn’t afraid of playing spoiler to the establishment-favorite Hurt. He even suggested his third-party candidacy could help freshman Rep. Tom Perriello (D-Va.) stay in Congress.

“It may amount to only drawing enough votes from the Republican candidate to ensure Tom Perriello a second term,” Rees told the Lynchburg News and Advance.

“If so, so be it. Maybe then the party will understand that we are trying to save the GOP from its worst enemy — not the Democrats, but themselves.”

A similar situation occurred in Rep. Mary Jo Kilroy’s (D-Ohio) district last year, when Republican Steve Stivers lost enough of the vote to conservative third-party candidates to allow Kilroy to win.

And now Stivers, who supports abortion rights, could again be ceding support to his right, in the form of Ron Paul supporter David Ryon. Ryon switched from the GOP to the Constitution Party this week.

It should be noted that Kilroy and Perriello each won by less than 1 percent in 2008, making them among the closest races in the country. In fact, both races were drawn out past Election Day because they were so close.

Those are the races where third-party candidates can make a difference.

It should be noted that neither Ryon nor Rees appears to have cited Hoffman in his announcement, so any connection to the New York race appears to be indirect. But even if they were unaware, the underlying factors that led to their decisions — and Hoffman's — could be troubling for the GOP.

UPDATE: A reader points to another example – independent Rob John, who has suggested Montgomery City Councilwoman Martha Roby is not a true conservative. Roby is the GOP frontrunner in another top-targeted race, against Rep. Bobby Bright (D-Ala.).