Donald Trump's campaign has decided to close up shop in the key battleground state of Virginia, in a bid to concentrate its resources in more competitive states, two senior campaign sources told ABC News.

The move effectively concedes the state and its 13 electoral votes to the Democratic presidential ticket of Hillary Clinton and former Virginia Gov. Tim Kaine, who’s now the state’s junior U.S. senator.

Polling conducted this month by Roanoke College gave Clinton a 9-point edge among likely voters in the state — 45 percent to Trump's 36 percent.

The Trump campaign Monday fired its chairman in Virginia, Corey Stewart, for organizing a demonstration outside the Republican National Committee headquarters in Washington, D.C., after numerous Republicans withdrew their support for Trump amid revelations of lewd 2005 comments he made about women.

In a post on Facebook, Stewart protested the campaign's pulling out of Virginia, saying his home state is "winnable" and calling the move a "betrayal."

ABC News' John Santucci contributed to this report.