The Republican field running to succeed retiring Sen. James Webb (D-Va.) could get a bit more crowded in the coming weeks: the owner of a Great Falls-based media production company is mulling whether to jump into the race.

Timothy E. Donner -- the executive director of Horizons Television Inc. and the head of a conservative public policy organization — is weighing whether to join a GOP primary that already includes ex-Sen. George Allen as well as tea party leader Jamie Radtke and Hampton Roads lawyer David McCormick. Former Gov. Timothy M. Kaine, the current Democratic National Committee chairman, is “increasingly likely” to run for the Democratic nomination, his spokesman said this week.

Donner’s interest in the race was first reported by Politico.

Jim Dornan, a vet­eran political operative who has been advising Donner, said Friday that “the decision will probably come in the next two to three weeks at the latest. He’s talking to family and friends. He’s being very deliberate about this.”

According to its Web site, Horizons has been in operation since 1986, producing educational, fundraising and training videos as well as documentaries. Donner is also president of One Generation Away, a nonprofit public policy group that describes itself as “committed to restoring, strengthening and preserving the vision of a free America.” And Donner serves on the board of directors of the conservative Virginia Institute for Public Policy.

Donner is not well-known in Virginia Republican circles, has never run for office before and appears not to have made any contributions to state or federal candidates.

“He has not been involved politically beyond the policy world,” Dornan acknowledged. “This is brand new to him.”

But Dornan said Donner “saw what was going on in the Senate race and said wait a second, we can do better than this.” Dornan said he could not name a policy issue on which Donner disagreed with Allen or Radtke, but said Donner could fill the niche of “citizen legislator” in the race, without the “baggage” of having previously held office.

The 2012 Senate race is expected to be expensive, and Dornan said Donner has “got the resources” to run a competitive campaign, though he did not specify how much money Donner might be willing to spend.