Matchups among all American voters show:

Biden tops Trump 48 – 40 percent. He beats Bush 45 – 39 percent and gets 44 percent to Rubio’s 41 percent.

Clinton edges Trump 45 – 41 percent. She gets 42 percent to Bush’s 40 percent and gets 44 percent to Rubio’s 43 percent.

Sanders edges Trump 44 – 41 percent and edges Bush 43 – 39 percent. Rubio gets 41 percent to Sanders’ 40 percent.