The first general-election ad of Robin Carnahan’s Senate campaign does little else but attack GOP rival Roy Blunt for his role in the bailout of Wall Street in late 2008.

Carnahan’s response, at a big-money fundraiser, to a donor who argued that if the bailouts hadn’t happened, the country would have faced worse financial problems: “Absolutely.”

Look, I’m sure somewhere, deep down, Robin Carnahan has principles, but she can’t be expected to stand up for them when there are big campaign donations at stake.