Here is an interesting article about why big government IT projects fail so often, even more often than the typical private sector ones. The reasons the article gives are all very interesting but leave of the most obvious one.
In IT projects, failure is more likely when IT project goal do not align with the companies business goals. In other words you always must remember what the ultimate business of the company is make sure that all IT systems must ultimately enable those goals.
In the government sector there are no business goals.