Kammala wannan jumla: A ranar 3 ga Fabrairun 2008, Shriver ya goyi bayan Sanata Barack Obama don zaben shugaban kasa na 2008. An bayar da tallafin ne a wani gangamin UCLA wanda ya hada da Caroline Kennedy (dan uwan Shriver), Oprah Winfrey, Stevie Wonder, da matar Obama Michelle Obama. Gwamna Schwarzenegger ya goyi bayan Sanata John McCain don zaben shugaban kasa na Republican 'yan kwanaki da suka gabata a ranar 31 ga Janairu, 2008. Daga baya a wannan shekarar, kamar yadda a 2004, Shriver ya halarci
taron kasa na jam'iyyar Democrat lokacin da kawunta Ted Kennedy ya yi magana.