It's 3AM, Do You Know Why This Ad Matters?When Hillary Clinton played on doubts about the readiness of her opponent Barack Obama, she made clear the race wasn't over.It's 3AM, Do You Know Why This Ad Matters?03:58Get more newsLiveonNBC News NowPrintJuly 12, 2016, 2:01 PM UTC / Updated July 12, 2016, 2:01 PM UTC