Dan Eggen in the Washington Post today claimed that a few hundred thousand dollars spent in a U.S. House of Representatives election can swing the result. Are there examples of this occurring? I am somewhat dubious of his claim, which he does not back up with evidence at all.
He’s just quoting the conventional wisdom. There is no evidence to support this, it’s just what most people believe, so he doesn’t need to prove it.
Well, he is partly right. If we assume a race where an incumbent has raised $400,000 and his challenger has $50,000, the incumbent is pretty much certain to win. But if a Super PAC comes in and spends $350,000, then that could very well get the challenger enough exposure to overcome an incumbent. Thus, the election has been “swung”. 
But to me, that’s not a problem. I don’t see how anyone could consider that situation to be a problem. Other than the incumbent of course, who will go on TV and lament how money has corrupted politics. And the friends in the media who he has built up relationships with over the years will portray him in the most sympathetic light.
In Kansas, formerly a fairly moderate conservative state, now more like Alabama or Mississippi:
If Obama wins, and the rest of the ticket loses, Obama might as well have lost.