Kind of false kind of true, 100% overblown smear campaign. The donations came from people who are members of CAIR (center for American and Islamic relations). A group pegged as a terrorist organization in Florida, Texas, and the United Arab Emirates (which to me is a green flag in CAIR's favor, lol)
They've vocally opposed Israel's invasion and supported Hamas in defending Palestinians but have historically denounced Hamas terrorist actions.
So, yeah, they're Hamas linked, but in a "they're the people fighting Israeli occupation" kind of way.
Edit to add: as far as I can tell the donations were personal donations by people who happen to be members of CAIR, not from CAIR itself even. Making it even more overblown smear when compared to, say, 60 million straight from AIPAC that others had received