Looking for clues on Barack Obama's pick for a running mate? Consider the Democratic convention's theme for the night the vice presidential candidate speaks: national security.

Political tea leaf readers would argue that bodes well for Senate Foreign Relations Committee Chairman Joe Biden, D-Del.; Republican Sen. Chuck Hagel of Nebraska and Democratic Sen. Jack Reed of Rhode Island, who accompanied Obama on his trip to Iraq and Afghanistan; and Sam Nunn, former Georgia senator and one-time Armed Services Committee chairman.

Democrats, who announced several of their speakers on Sunday, described their themes on Monday as well as plans for a series of town-hall meetings during the convention with elected leaders and policy experts. The convention begins Aug. 25.

"There's no question that Americans are desperately looking for change and new ways to conduct business in this country. They want a new direction, they want to know that their government has not forgotten them and their lives. We felt that the Democratic convention was a great way to kick off the momentum for change," said Kansas Gov. Kathleen Sebelius, a co-chair of the convention who also has been mentioned as a possible vice presidential pick.

She said people in eight cities will be asked their views on nightly themes for the convention built around keynote speeches and convention speakers will respond live to issues and questions from participants. The cities are Atlanta; Columbus, Ohio; Denver; Detroit; Philadelphia; Raleigh, N.C.; Richmond, Va.; and Tampa — all are in potential swing states.

The theme for the Aug. 25 opening night will be "One Nation," with a speech by Michelle Obama. The Aug. 26 theme is "Renewing America's Promise" with a speech by Sen. Hillary Rodham Clinton, Obama's chief rival for the presidential nomination.

On Aug. 27, the theme is "Securing America's Future" with an acceptance speech by Obama's still-unannounced vice presidential candidate.

The theme for Aug. 28, the night Obama formally accepts the nomination at the Denver Broncos' football stadium, is "Change You Can Believe In."

Marcia Hale, who helped plan conventions for Democrats Michael Dukakis and Al Gore, said political conventions need to change to keep a television audience and take advantage of new media like the Internet. She said recent conventions have been more like coronations than spontaneous political events.

"Anything you can do to change and modernize the convention is positive. One of the biggest challenges is putting up something television will cover and people will want to watch," she told The Associated Press.