Kammala wannan jumla: An bayyana ra'ayoyin siyasa na Duvall a matsayin masu sassaucin ra'ayi ko masu ra'ayin mazan jiya. An gayyace shi da kansa zuwa bikin rantsar da Shugaban Republican George W. Bush a shekara ta 2001. A watan Satumbar 2007, ya sanar da goyon bayansa ga dan takarar shugaban kasa na Republican Rudy Giuliani. Duvall ya yi aiki a bene a GOP ta
Babban taron kasa na 2008 kuma, bisa ga labarin MSNBC na 29 ga Agusta, 2008, Duvall ya ba da labarin yawancin bidiyon taron. A watan Satumbar 2008, ya bayyana a kan mataki a wani John McCain  Sarah Palin gangamin a New Mexico.