Money for Nothing
A friend points out to me that both John McCain and Barack Obama have agreed to accept matching funds and abide by spending limits for the general election if their opponent also agrees to do so. Hillary Clinton, by contrast, has made no such pledge. If you're a hard-core campaign finance reformer I guess this is a reason to support Obama. But if you're a normal person, it looks like a strategic mistake on Obama's part; he'd seem to be forfeiting a potentially large financial advantage.
This gets especially problematic when you think about the intervention of outside groups. It's fairly easy for, say, a group of insurance companies to just decide to each pony up some cash and run ads attacking a candidate who they think is bad for their interests. By contrast, it's hard to see Obama's small- and mid-sized donor base spontaneously organizing itself into a viable independent expenditure group.