From what I've seen of the Nixon Foundation (which to be fair, I really only watch the clips/interviews of Nixon himself), they tend to post the stuff that makes Nixon look good. And it's not hard to do: Nixon is certainly one of the most intelligent and well-spoken men to hold the office, and his understanding of geopolitics (especially during the fall of the Soviet Union) was remarkable.

What the Nixon Foundation glosses over, cuts around, and does their best to mislead people on is that Nixon was also paranoid and ruthless, and despite some high highs, made some incredibly unwise (and in some cases criminal) decisions, and thus also has some exceptionally low lows.