The Rasmussen Reports daily Presidential Tracking Poll for Thursday shows John McCain's lead growing against both potential Democratic opponents. McCain currently leads Barack Obama 49 percent to 42 percent and Hillary Clinton 51 percent to 41 percent margin. African-American support for Clinton has collapsed, falling to 55 percent in the general election match-up. Obama, on the other hand, earns solid support from African-American voters but attracts only 36 percent of white voters in a match-up with McCain. Over the past month, McCain has gained ground in Ohio, Michigan, Colorado, New Hampshire, and Pennsylvania. Both Democrats continue to lead in New York, Massachusetts, Connecticut and California (see summary of recent state general election polling).