Who does Michael Douglas think he is?

Aaron Sorkin wrote The American President before The West Wing. That much is obvious. It's interesting to watch as messed-up preview of The West Wing, where everything is out of place and rearranged. It's a shame the film follows the slightly dull conventions of Hollywood romance, but there's enough other stuff going on to make it watchable. And it's still Sorkin. Here's some similarities between the two, both in cast and writing:

• Martin Sheen plays the Chief of Staff. This is just wrong. This man is the President of the United States. Who does Michael Douglas think he is? Like Bartlet and Leo, these two are old friends. But they play pool instead of chess. And to be fair, Douglas does a good POTUS.
• Joshua Malina turns up. That's all, really.
• Anna Deveare Smith plays the Press Secretary. I had to look that name up, but she played National Security Advisor Nancy McNally. She was always around.
• Ellie, who had a whole episode named after her, has a minor role here. Not the character, the actress. Nina Siemmaszko.
• Michael J. Fox, who plays the 'Assistant to the President for Domestic Policy' (lets say Deputy Chief of Staff) is a lot like Josh Lyman. He gets worked up easily. He's completely obsessed with the job. And he has a similar moment to Josh's 'take your legislative agenda and shove it up your ass' rant. But with more swearing.
• The relationship between the President and his daughter has some similarities to Bartlet and Zoey. 'You're going to make me read this book cover to cover and then ask me a thousand questions about it at dinner'. Or something like that.
• 'What is the virtue of a proportional response?' That came up pretty early in Season One.
• The President says 'What's next?' The final words of the pilot and the line that was missing from the last episode.
• Finally, and probably most importantly, the writing feels similar. The rhythm of the dialogue, the walking and talking, the sheer amount of stuff happening in each sentence. And the big speech at the end could have been straight from Bartlet. If it wasn't about the President's new girlfriend.

There's probably more, but I haven't seen The West Wing that many times to notice. Or maybe I have. The question is, was The American President the practise run or the inspiration?