This makes the current state of law somewhat unusual - according to Citizens United, money is speech, yet boycotts aren't.
Perhaps there is some "hidden variable", common to both cases, yet not obvious to the casual observer, that unites the two cases.
The cases share some features, and differ in others, so it's not entirely unreasonable that their 1st amendment protection differs. But it's a very interesting contrast nonetheless.
I was thinking more along the lines of the two cases are "money is speech if you do something we like" (Donate) and "money isn't speech if you do something we don't like" (BDS), where the common factor is just "what we like". Because that's how it looks to me.
to be fair, thats how it seems the 'constitionality' of most laws is determined..