WASHINGTON -- There's speculation about whether Dayton will be the place where Sen. John McCain, R-Ariz., plans to announce his running mate.

Although McCain's camp has yet to make this official, key Ohio Republicans have revealed that they've been ordered to start rounding up a crowd of 10,000 for a rally next Friday at the Ervin J. Nutter Center.

News Center 7's Carol Han asked political expert Patricia Murphy, citizenjanepolitics.com, why McCain may choose Dayton to reveal his choice for Vice President.

"John McCain cannot afford to lose Ohio," said Murphy. "George Bush won Ohio both times, and in 2004, Ohio provided the margin of victory for him."

When asked why Dayton may be picked over other Ohio cities, Murphy called it the perfect backdrop for McCain to reach out to the voters he needs to become President.

"I think it's the perfect all-American town. It's going to be a great backdrop for the rest of the country, to the people he's appealing to: working place people, people who are not on the coast."

As for the supposed date of the announcement-- a week from Friday-- that's a day after Barack Obama accepts his party's nomination. Murphy says McCain may choose to make the big reveal on that day to slow Obama's momentum.

In addition, Aug. 29 is McCain's 72nd birthday. News of his running mate would take unwanted attention away from his age, Murphy explained.