A new poll from Gallup shows that in an Obama vs. McCain race 28 percent of Hillary ClintonHillary Diane Rodham ClintonWoman behind pro-Trump Facebook page denies being influenced by Russians Trump: CNN, MSNBC 'got scammed' into covering Russian-organized rally Pennsylvania Democrats set to win big with new district map MORE's supporters would vote for McCain. If the race is Clinton vs. McCain, 19 percent of Obama's supporters would jump to McCain.