Dear Neil,
for me it was not replaced. The Political Machine 2004 had a much smoother gameplay for me, and I like its graphics better. I don't like 3D, and for this kind of game I think it is unnecessary. Also the portraits are much better in PM2004 than in later versions. The colors are much better, it has many more shades. Also, at the end, when you see the states going red or blue, they are not lifted up. And also, the speed of PM2004 is bigger, in my PC later versions are slow and sluggish.
All in all, I want to play PM2004 and not 2008 or 2012. Why is it not available?