Public Funding - What is the issue?

Barack Obama has declined to use public funding for his general election campaign despite earlier clues that he would use it, and some people seem none too happy about it. I don't know a ton about it, but it all seems to be a mixed bag. I think spending limits are good (public funding would place a ceiling at 85 million dollars), but does it really limit spending if you've got lobbyists and special interest groups that can still spend a virtually unlimited amount? Is there any way to actually limit spending? Do private donations encourage political favors - even in relatively small amounts? (A great site to check for up-to-date numbers is OpenSecrets - find out where the money is coming from and where it's going to)

I don't know... does it matter as an campaign ethics thing or will campaign spending pretty much just stay out of control no matter which way you spin it? Anyone have an opinion on the topic?

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