Massachusetts Gov. Deval Patrick will participate in a panel discussion about the Democratic Party during the Democratic National Convention next month. The John F. Kennedy Library Foundation will host the discussion, "Changing Political Demographics and the Future of the Democratic Party,'' on Sept. 5 at the convention in Charlotte, N.C. Boston Mayor Thomas Menino will kick off the event, which will be moderated by David Gregory, host of NBC's "Meet the Press." Patrick is one of the co-chairs of Obama's re-election committee and a surrogate for Obama.