ON THE TRAIL: Thursday, May 22, 2008

Compiled by Mary Grace Lucas, CNN Washington Bureau

* Sen. Hillary Clinton is in DC today and is expected to appear at the Armed Services Committee hearing where Gen. David Petraeus and Lt. Gen Ray Odierno may face a grilling from Senate Democrats about troop levels in Iraq.

* Sen. John McCain speaks at a roundtable, holds a media availability and then heads to an afternoon rally in California.

* Sen. Barack Obama holds a town hall meeting at noon in West palm Beach, Florida.