Obama’s four challenges tonight… Clinton comes to the president’s defense… He also praises Bush, while lashing out at “hate” of GOP… The danger of the Romney campaign elevating Clinton… Before Clinton’s speech, however, Wednesday was a day full of headaches for the Democrats… A diminished Biden… Obama camp releases “Promises Kept” video, while RNC unveils “The Breakup” ad… And Romney to do “Meet the Press” this Sunday.

By Chuck Todd, Mark Murray, Domenico Montanaro, and Brooke Brower