Carly Fiorina, former GOP presidential hopeful, says she will not run for the U.S. Senate from Virginia next year. (Cliff Owen/AP)

A decision by Carly Fiorina, the former GOP presidential hopeful, not to run for U.S. Senate from Virginia next year leaves Corey Stewart, the bombastic Prince William supervisor, as the sole declared candidate for the GOP nomination.

Stewart, who came close to winning the party nomination for governor this year after running on a platform dedicated to protecting Confederate statues, said Fiorina's absence from the Senate race clears the way for him to challenge Sen. Tim Kaine (D).

Several political observers agreed.

Upon hearing of Fiorina’s announcement, Tom Davis, a former Republican congressman from northern Virginia who is known as a moderate, said: “That makes Corey the undisputed frontrunner at this point. That wraps it up.”

“I do think he’ll be tough to beat in a primary or a convention,” Davis added. “The Republican Party has moved from the country club to the country.”

John Fredericks, host of a conservative radio show and co-chair of Trump’s Virginia campaign after Stewart was dismissed from that role, called Stewart the “prohibitive favorite” barring a “political earthquake.”

Other potential hopefuls may be hesitant to “go through the Corey Stewart buzz saw and take on a somewhat popular incumbent,” Fredericks said.

The general election, however, may turn on whether Republicans can beat Democrats in statewide elections this year. All five of the statewide offices are currently held by Democrats. If Ed Gillespie can reverse the trend and win the governor’s race, more Republicans may enter next year’s race for Senate.

Kaine downplayed Fiorina’s decision.

“Republicans may still have a primary - and it would be competitive - so we will let that play out,” campaign spokesman Ian Sams said in a statement.

Kaine, a popular former governor and Hillary Clinton's vice presidential running mate in 2016, is seeking a second term in the Senate. A February poll found him with a double-digit lead over potential Republican challengers, but that was before Stewart declared his candidacy.

In interviews with other media, Fiorina did not say if Kaine’s popularity discouraged her from running. Through a spokesman, she declined an interview with the Post.

“One of the reasons I’m not [running] is because I so passionately believe that I can actually make a bigger impact not running for the U.S. Senate, but bigger impact lifting up leaders wherever they are,” she told the financial website The Street.

Conservative radio host Laura Ingraham took herself out of the running for the Senate race earlier this summer and has said she will help Stewart.

Virginia GOP Chairman John Whitbeck lamented Fiorina’s decision but said he expects more candidates to emerge before the Senate primary next year.

Asked whether he was concerned about Stewart, who has been associated with extremist groups, being the face of the party, he said: “It would concern me if anyone was associated with white supremacists, the KKK, white nationalists and called themselves a Republican. We absolutely reject such groups as being in any way associate with us. They’re not conservatives. They’re bigots and racists.”

Stephen J. Farnsworth, a political scientist at the University of Mary Washington, said tension between the state party and Stewart is reason enough for others to join the race.

“Is running against Corey Stewart a pleasant activity?” he said. “Of course not. But if people want a pleasant activity electoral politics is probably not a good idea.”

Besides Stewart, at least two other Republicans — former Gov. Jim Gilmore and Del. Jimmie Massie (R-Henrico) — have said they are considering running for the party nomination to challenge Kaine.