I'm a little cynical about the effectiveness of traditional advertising, so this post comes with a grain of salt. Barack Obama managed to raise $50 million in a month because he was able to leverage the power of the Internet. He had no shortage of funds or supporters, and there's probably not a simple answer, but:

Did he win the election in 2008 because he had the money?

Did he win the election because he got the money; not because of the money, but because it rallied voters around him?

Did he win because contributors felt attached to him after contributing to his campaign?

There's probably a correlation between how much money a political candidate spends on their campaign and how likely they are to win. Me, I think Obama got all that money because he stood for something that people had an easy time believing in. He didn't win because of the money, and yet, if hadn't been able to raise it, he probably wouldn't have won. The support had to come first.