Obama said Trump doesn't know his "stuff" and doesn't want to learn.
"Funny how the failing @nytimes is pushing Dems narrative," Trump tweeted.
"No recognition - SAD!"
Obama, Biden and Kaine highlight the star-studded lineup.
They are betting that a shift in voter sentiment has turned a once-toxic issue into a political winner.
PHILADELPHIA — Clinton largely ignored the most tumultuous period of his White House tenure.
Priebus did not mention the unpopularity of his own party's nominee, Donald Trump.
PHILADELPHIA -- "We just put the biggest crack in that glass ceiling yet," she said.
Bill Clinton said Democrats had nominated the "real" Hillary Clinton as president.
Clinton praises his wife, Hillary, after her formal nomination