Virginia has a large concentration of military personnel and defense-related businesses and Obama has poured a lot of resources into the state, hoping to score a rare Democratic win there.

Obama is eight points ahead in Virginia, according to the latest Real Clear Politics average of presidential polls.  

Rep. Debbie Wasserman Schultz (D-Fla.) said Powell’s endorsement will also resonate strongly in Florida, another battleground state.

“We have thousands of military retirees in the state of Florida. And I think what Colin Powell's endorsement does say is it shows that Barack Obama can build bridges across party lines,” she said on the same program. Polls show Obama three points ahead of McCain in the Sunshine State.

Powell was chairman of the Joint Chiefs of Staff under President George H.W. Bush before becoming secretary of State in the first term of President George W. Bush. A Republican, Powell is one of the most highly decorated military officers and is admired in both parties.

Some Republicans are downplaying Powell’s endorsement of Obama. Missouri Gov. Matt Blunt (R) said he did not think that Powell’s support will make a difference in his state, another battleground.

“Missourians admire Colin Powell for his many years of service to our country, but in the end they’re going to evaluate where the candidates are on issues that are important to them, [such as] taxes, growing our economy, creating more wealth rather than redistributing existing wealth, protecting innocent life, protecting second amendment rights, and all those issues,” he said on Face the Nation. “Sen. McCain obviously lines up with the values of Missourians.”

Former Rep. Rob Portman (R-Ohio), also Bush’s former budget chief, also doubted that Powell’s endorsement would help Obama in Ohio.

“Endorsements are typically overrated I think,” he said. “But Colin Powell is well respected. I was interested to see that he said this morning that he thought either man would be a good president.”