But I couldn't help but notice that this Jewish-American organization is protesting the right person - Trump.

It's an interesting contrast to the many pro-Palestinian groups who appear to exclusively protest Democrats and random Jewish people.

This group got it right. Naturally, they were arrested.

"the Israeli government’s blockade of Gaza is a policy of ethnic cleansing by way of forced mass starvation,” said Morriah Kaplan, IfNotNow’s interim executive director (emphasis mine).

Note that Gaza was ethnically cleansed of Jews in 2005. The Jewish Gazans even had to dig up and take their ancestors' Jewish graves with them.

Wow. I wonder how you would feel if it was Palestinians who had the tanks, bombers and US dollars to level half of, say, Judea while systematically starving the survivors.

The bombing and starving would stop tomorrow if Hamas would just surrender and disarm, as the Arab League is telling them to do.

This refutes the antisemitic lie that all Jewish people are in agreement with Netanyahu. That lie is promoting antisemitic attacks on Jewish people.

TIA

to prove one's anti-establishment outsider purity never took off as a tradition.

And the reply is (often and amusingly) "Well, we're actually already doing the thing you want us to do!" --- But the most aggravating ones are when the protestors are making demands that cannot be legally or procedurally accomplished, especially without a majority or even a super-majority... or even a constitutional amendment. And, you're right, fortunately that didn't become a tradition, but there are enough naive folks who lack a full understanding of what's actually doable and rather than focusing on those things, the pie-in-the-sky impossible demands end up preventing the possible from happening. People want what they want and they want it now, without regard to the best way to get from here-to-there, or without regard to the actual steps needed to make things happen in meaningful and sustainable ways. As per usual, the "perfect" becomes the enemy of the possible... and a path to better, and a road to perfection is never cleared for others to follow.