HUD Secretary Julian Castro will endorse Hillary Clinton for president next week in San Antonio, ramping up speculation that he’s on her vice president running mate shortlist. 

As Republicans search for someone to succeed John Boehner as speaker of the House, some have suggestedbringing in an outsider, such as former House speaker Newt Gingrich or Colin Powell, the former secretary of state and onetime chairman of the Joint Chiefs of Staff. The Constitution is silent on the question of whether the speaker must be a member.