Please tell me why presidential canidates have to raise so much money?

I understand why they need so much money, but it still makes me sick. So many of the problems the candidates are talking about fixing could be easily fixed with all the money they are spending on their campaigns. Clinton raised $4 million in just 24 hours after Super Tuesday, why are people so willing to give at these levels??

Here are some answers about what they use the money for.

What do you think?