Non-citizens or immigrants living in the United States are covered by the U.S. Constitution, the First Amendment to which protects the right of peaceful assembly. However, the practical reality of taking part in street protests or marches, even if they are legal and peaceful, is a bit more complicated. You could, whether you have a green card, some other legal status, or DACA (Deferred Action for Childhood Arrivals), be risking your right to remain in the U.S. if you are singled out or arrested by immigration or law enforcement authorities.
U.S. immigration law (I.N.A. Section 237) sets forth numerous grounds upon which a non-citizen may be deported (removed) to their country of origin. Taking part in lawful, peaceful protests is not on that list.
But other grounds of deportability can be used against protesters, for example the one making foreign nationals who endorse or espouse terrorist activity deportable. The second Trump administration has used this to define pro-Palestinian protesters as terrorists and then seek to deport them. (See for example, the case of Mahmoud Khalil.) What's more, various U.S. states' legislatures are considering anti-protest bills. (See US intensifies crackdown on peaceful protest under Trump.)
Also, if a protest were to get unruly or violent, you could find yourself committing or being arrested for acts that ARE specified on the list of deportability grounds or crimes of the sort that cause DACA holders to lose status. Both of these possibilities are discussed below.
The following are grounds of deportability that could be used against any non-citizens, whatever their immigration status, if they're arrested or picked up by police or immigration officials during a protest:
The tricky thing is that the federal-law definitions of what makes someone deportable are meant to encompass a wide range of crimes, many of them found in various states' criminal laws. No one is ever convicted of a "crime of moral turpitude," for example. But people convicted of crimes such as aggravated assault, theft (such as looting), and mayhem have been found by U.S. immigration authorities to have committed crimes of moral turpitude and to thus be deportable from the United States.
Of course, if you are in the United States with no lawful status in the first place, you are already considered deportable, with only a few potential defenses available to you. U.S. immigration authorities (Immigration and Customs Enforcement, or ICE) have been known to show up at public protests. If they decide to question or arrest you, you could land in removal proceedings.
DACA holders can lose their immigration status or be denied DACA renewal and face possible deportation for:
The term "significant misdemeanor" covers a variety of criminal convictions. Most notably for would-be protesters, these include crimes where a sentence of more than 90 days was imposed, or involving firearms, trespass, or disturbing the peace.
Take particular caution if you are in the United States with no right to remain here other than DACA.
You have a legal right to have your voice heard in the United States. But be realistic, and don't go to any protest without a plan for how you will stay safe and in communicate with others who can help you if the worst happens.
This might include, for example, surrounding yourself with friends, letting family members know where you'll be, carrying a cell phone with which to take videos, and memorizing the phone number of a criminal attorney and an immigration attorney to contact if things go wrong. Make yourself aware of how the protest is organized. In some cases, the organizers will specifically look for volunteers to put themselves forward for arrest. You probably don't want to volunteer for that.
Also review your rights in the event of arrest, such as the rights to remain silent and to refuse to show identity documents that say what country you are from.