Why does it cost so much for a political campaign?

[Jester]

Some of my co-workers and I were discussing this and wondered, why are politicians so proud of their huge campaign war chests? The raise millions of dollars, spend a large bit of it on the campaign, and what happens to it after the fact? I'd love to see someone try to run a bare bones campaign, and whatever money they don't spend on the campaign, donate it to lower the debt or something. With modern technology it'd seem a political campaign could probably do well with limited funds, if it just used them well.

What are your thoughts? Would you vote for a candidate who said, "Thank you for your donations. Know that I will try to use them wisely and use as little as possible and what I don't use, win or lose I will give to some charity/pay down the national debt/ect."?