There are a few laughs with the fish out of water scenes we get once Kline is the President but the rest of the movie plays out as you would expect. The good guys wins and the bad guy doesn't.
The cast is well rounded and they all did a good job.
Kevin Kline pulls double duty in Dave. Kline plays both President Bill Mitchell, knocked out of commission during an extramarital tryst, and Dave Kovic, an occasional presidential impersonator secretly brought in to act the part on a long-term basis. While Mitchell had been foundering in office, Dave turns out to be a natural, proving that even a simpleton can do the job. Oh...
President Speak: "You don't really know how much you can do until you, stand up and decide to try."
And this is a perfect example of a Sunday afternoon movie. If it had a few more teeth and took the odd risk it would have been great. As it is, this film is completely harmless to you and your family, and enjoyable enough for it.