Julián Castro quit the 2020 Democratic primary.<br />The dropout comes just weeks to go until votes begin.<br />Business Insider says he had trouble getting name recognition, in part because of DNC debate eligibility requirements. <br />Castro is now a sought-after endorsement.<br />He is now on top of any Vice Presidential contender list.<br />Some candidates will benefit from Castro's departure.<br />A third of Sen. Amy Klobuchar's supporters like Castro as well as a quarter of Mayor Pete Buttigieg's.