"There is billions of spending on projects they don't need"

On the list of governemnt expenses... NASA is almost a rounding error ($18.4 billion in 2011, about 0.5% of the $3.4 trillion US budget). Perspective is important.

I think their point may have been (and if it wasn't, mine is) not to cut that funding but to reallocate it to more oversight so the overall pace of space production and research can be expanded.

Yes my point is not that nasa is a bad thing - I want to increase spending at nasa. But I don't want it to be wasted on basically congressional district earmarks. There's always been some of that going on, unfortunately, but the SLS is a major drain on other things at Nasa. They can't afford to waste money on this. SLS may never fly, it's at least a big rocket looking for a use case.

The problem seems inherent in large engineering projects (> 2 terms worth of work) and the ephemeral nature of politicians.

I feel like there's probably a "law" using a constant that states "As a project's ETA approaches T, the actual delivery date approaches infinity."

Where T is ~10 years.