My favorite The Campaign story was as we were driving home after the film, we stopped and got a few things and then after leaving those shops on the drive home I was trying to figure out how I spent my day. I literally forgot that I had seen that movie thirty minutes later. So, yea, I'd say forgettable sums it up pretty nicely.
I think Galifinakis can be really good, but he hasn't gotten much to work with in the movies he's made.
I've never been a big fan of Ferrell's movies though. Comic actors these days (or maybe in general?) seem to play the same character every time out. Burgundy, Ricky Bobby, the campaign guy all seem really similar and rely on the same approach for laughs. I do like Ferrell's work, I just have a tough time sitting through 90 minutes of it at once.