Sen. Hillary Rodham Clinton, D-N.Y., left, listens to Sen. Charles Schumer, D-N.Y. during a news conference to open the Erie Canal Harbor Development Project in Buffalo, N.Y. on Wednesday, July 2, 2008. (AP Photo/Don Heupel)

Sen. Hillary Rodham Clinton, D-N.Y., speaks at a campaign event for Democratic presidential candidate Sen. Barack Obama, D-Ill., in Unity, N.H., Friday, June 27, 2008, their first joint public appearance since the divisive Democratic primary race ended. "Well, Unity is not only a beautiful place as we can see, it's a wonderful feeling isn't it? And I know when we start here in this field in unity, we'll end on the steps of the Capitol when Barack Obama takes the oath of office as our next president," said Clinton. (AP Photo/Elise Amendola)

Sen. Hillary Rodham Clinton, D-N.Y., greets airport workers prior to boarding a campaign charter plane with Democratic presidential candidate Sen. Barack Obama, D-Ill., Friday, June 27, 2008, at Washington's Ronald Reagan National Airport. (AP Photo/Alex Brandon)

Sen. Hillary Rodham Clinton, D-N.Y., steps out of the car prior to boarding a campaign charter plane with Democratic presidential candidate Sen. Barack Obama, D-Ill., Friday, June 27, 2008, at Washington's Ronald Reagan National Airport. (AP Photo/Alex Brandon)

Sen. Hillary Clinton, D-N.Y., enters a fundraiser also being attended by Democratic presidential candidate Sen. Barack Obama, D-Ill., at a hotel in Washington, Thursday, June 26, 2008. Clinton lauded Barack Obama for "his grit and his grace" as she resumed public and private campaigning Thursday to support the candidate who dashed her hopes of winning the Democratic presidential nomination. (AP Photo/Alex Brandon)

Sen. Hillary Clinton, D-N.Y., leaves a fundraiser held with Democratic presidential candidate, Sen. Barack Obama, D-Ill., in Washington Thursday, June 26, 2008.(AP Photo/Alex Brandon)

Sen. Hillary Clinton, D-N.Y., enters a fundraiser also being attended by Democratic presidential candidate Sen. Barack Obama, D-Ill., at a hotel in Washington, Thursday, June 26, 2008. Clinton lauded Barack Obama for "his grit and his grace" as she resumed public and private campaigning Thursday to support the candidate who dashed her hopes of winning the Democratic presidential nomination. (AP Photo/Alex Brandon)

Sen. Hillary Clinton, D-N.Y., enters a Democratic fundraiser, also attended by Democratic presidential candidate Sen. Barack Obama, D-Ill., (not shown) at a hotel in Washington, Thursday, June 26, 2008. Clinton lauded Obama for "his grit and his grace" as she resumed public and private campaigning Thursday to support the candidate who dashed her hopes of winning the Democratic presidential nomination. (AP Photo/Alex Brandon)

Sen. Hillary Rodham Clinton, D-N.Y., right, walks with House Speaker Nancy Pelosi of Calif. on Capitol Hill in Washington, June 25, 2008, following the House Democratic Caucus meeting. (AP Photo/Susan Walsh)

Sen. Hillary Rodham Clinton, D-N.Y., addresses the National Association of Latino elected and Appointed Officials Conference, Thursday, June 26, 2008, in Washington. (AP Photo/Susan Walsh)