
Your "US" politicians were in fact Indiana state legislators (not federal - that is, US - politicoes). And they didn't try to say pi was 3 either - it was one of several values according to the bill introduced, none of them actually 3 as I recall. The bill was rejected anyway.
A little knowledge, eh? If the shoe fits ...
Anyway, if your judgement of units is based on how many Nobel physics prizes have been dished out by those defining, the slug is without recognition. And indeed it never was much used - Britain went to kgs, and Americans tended to use pounds-mass (ultimately referring to grams) - seeing the slug as a little-used "English" unit. Even though the English weren't using it at all.
If NASA want to talk about an orbital robot heaving pounds of stuff about rather than kilos, they can and they will, and it will make perfect sense to anyone normal.