Donald Trump appears to be zeroing in on a running mate. The presumptive Republican presidential nominee’s campaign has requested vetting documents from eight people, sources tell the Washington Post: GOP Sens. Marco Rubio, JD Vance, Tom Cotton, and Tim Scott; North Dakota Gov. Doug Burgum; Republican Reps. Elise Stefanik and Byron Donalds; and a member of his own former cabinet, Ben Carson, who served as secretary of housing and urban development. Coverage: Axios has a rundown on what Trump likes about some of the candidates, noting that the No. 1 thing the former president is looking for in …