I would and have told my kids that protesting without being part of wider community organising and action is more about feeling and wanting to appear right than doing the right thing. Actual community organising to bring about change takes a lot of unseen work, there are many ways to be part of movements that isn't putting oneself in the limelight or make oneself a target.
Protests tends to be glamorised with big movements of the past, it tends to get glossed over that they're only one small part of pushing for change and on their own very ineffective. Protests are also more likely than not to have people - whether with the government or just for laughs - who are there to disrupt it and bring wider society against the cause. Does he know how to spot that? Is he connected enough with the community to know how to deal with that?
Those hiding people from the Nazis or slavecatchers weren't making themselves targets. They were very specifically trying not to be seen by authorities. They were a very different part of the resistance from those who went out to kill SS soldiers or go all John Brown in the US south. Movements need different people trained and able for different things. Has he connected with any organisations to have training on how to handle the potential for violence nonviolently and know the local objectives beyond stopping ICE raids or is he just going along and hoping that him being there is going to somehow stop them? What is his plan beyond going to a protest - cause that's not a plan for change, that's a trip with political themes.
It's one thing to get swept up in the pain and rage against an oppressive force like we've seen in Iran and many other places - with very high horrific costs and sadly little benefit to it - it's another to basically take a day trip with a chance of getting and causing harm just because you think it's the right thing to do without any training before or plan for what comes next.
I have multiple citizenships, including UK and US, thankfully I didn't pass on the latter to my kids, and thankfully while my young adult and teenage kids have done protests, they chose low risk options with awareness that it was more about bringing communities together to organise and talk next steps than thinking having signs outside a government building was going to make any changes any time soon.