[flagged]
There are:
1) Naive college students who latch onto righteous political causes
2) Passionate lifelong anti-apartheid, anti-war activists who support the human rights of Palestinians
Neither of these groups are "Hamas operatives". Slinging a contentious slogan here and there is not that.
OTOH, the Israeli government is extremely interested in painting all opposition as "Hamas". And they've done so rather successfully.
Seems like they didn't have to try very hard. Many media outlets, talking heads, and politicians seemingly took the view from the start that anything less than full support for the Israeli government automatically makes you a pro-Hamas antisemitic scumbag.