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Cory Booker endorsed Joe Biden for president in a tweet on Monday, saying the former vice president will "show there's more that unites us than divides us."
Why it matters: Booker's approval is yet another endorsement for Biden from a former presidential candidate and the second from a black competitor for the White House. Sen. Kamala Harris endorsed the former vice president on Sunday.
Details: Booker and Harris are expected to appear with Biden at a rally in Detroit, just hours before Michigan holds its delegate-heavy primary on Tuesday, the New York Times reports.
- Booker will also campaign with Biden in Flint, Michigan, and attend a fundraiser with him earlier in the day.
The big picture: Biden has gained endorsements from at least 10 former candidates, including Harris, Pete Buttigieg, Amy Klobuchar, Beto O'Rourke and Mike Bloomberg.
- Bernie Sanders has so far received endorsements from former candidates Marianne Williamson and Bill de Blasio.
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