A tough double whammy for Hillary Clinton on Wednesday -- not only is Rush Limbaugh now backing Barack Obama for the Democratic presidential nomination, Clinton has lost George McGovern as well.

McGovern, a former representative and senator from South Dakota who was the Democratic presidential nominee in 1972, had been publicly backing Clinton. But on Wednesday, he came out for Obama and called for Clinton to leave the race. A friend of the Clintons, he said he called Bill Clinton to personally inform him of the decision -- he's also calling friends to urge them to make a similar switch.

McGovern told Fox News, "She's waged a very valiant campaign, but the mathematics [are] against her at this point. I don't see how she has much chance of pulling out the nomination now ... I think it's important for Democrats to get united to win the general election in November."