Harris made her announcement early this morning via Twitter and will rally with Biden in Detroit, Michigan on Monday night.
Source: CNN
(CNN) US Senator and former Democratic presidential candidate Kamala Harris has announced she will endorse Joe Biden for president.
"When I started my run for president, I said America needs a president who reflects the decency and dignity of the American people; a president who speaks the truth; and a president who fights for those whose voices are too often overlooked or ignored. I still believe that to this day. That is why I am proud to announce I am endorsing my friend, Vice President Joe Biden, for President of the United States," Harris said in a statement.
UPDATE: And then there's this.