This doesn't seem very well put into a single thing to me.

a paragraph by paragraph summary, which will be followed by why I disagree:

[summary starts here]

Trump is bad because he encourages oppression. People react to this in some ways that are not violent, and in some ways that are violent. "This isn't a coincidence."

Trump has incited violence, and his supporters have been violent in oppression flavored ways. Trump defies the norms of politics in a bad way, and groups try to make it seem like it is normal politics. Because Trump has encouraged violence, and violated norms of political discourse, it should not be surprising that people respond "in kind". Even if you think using violence is bad, you should agree that normalizing trump is bad. Violence reduced normalizing trump. Apparently liberals think that using violence is somehow worse than the bad things trump is doing / the normalization of trump.

Some people are saying that using violence to go against trump being normalized is bad, and people who say that it is good are criticized/punished. The people saying that it is bad are wrong because they blame the people responding with violence instead of the thing that the people being violent are responding to, they misunderstand the purpose of the violence, and they are like young children who don't know that sometimes violence is better than nonviolence for accomplishing things. [i.e. they are stupid/uneducated/childish for thinking that]

For the first part of that, it is ok to use violence because trump is moving the Overton Window, and is generally radically bad. Treating trumpishness like something that should be responded to in a way that respects norms in politics causes it to be more accepted as being a legitimate political viewpoint. This is unlike Cruz, who is also very bad, but is bad in a normal way.

Politicians and "liberals" act like the goal in resisting trump is to make trump not be elected president, but the real goal is to make it so the ideals associated with trump (trumpishness) do not become politically accepted as normal.

Trump is a result of republicans supporting oppression, and also "attacking the credibility of media, scientists, and the federal government". Stopping these systems of oppression is more long term than preventing trump from being elected. We can see why violence is useful in anti-fascism things from its usefulness in Europe as part of anti-fascism things.

Third, violence is useful because it helped reduce oppression in the past, as can be seen from a list of examples. [list not included in this summary] Fascism wasn't stopped in Europe because people elected a non-fascist but because other countries defeated the fascist countries in war. Also Hillary is a market centrist.

It is "problematic" for "people with privilege" to say that the use of violence to oppose trumpishness is wrong or illogical. Whether you would use violence doesn't impact your ability to understand justifications for it. Privileged people who argue that using violence is bad are oppressing those people who are too oppressed to be able to afford to determine if something other than violence would be enough to protect them.

[end of summary]

tl;dr: Author of article is a Marxist. Says that its fine for violence against trumpishness because oppression.

(note: I tried to be relatively fair in my summary, but because I disagree with the article, I cannot really be wholly objective about what it is saying, so if you are reading my summary instead of the article, bear that in mind I guess. Quotes are indicating that I am using the same wording in the summary as the article uses. Things in brackets are side notes.)

Worse than that, they are a Marxist that didn't even bother to put the things they were saying together. The main part where they make any sort of argument to attempt to morally justify the use of violence is just in the last paragraph. The rest of it mostly only argues that violence is useful. Well /duh!/ it is "useful"! Why do they think people use it? There are ends it can accomplish. When people are saying that violence is bad unless certain conditions are met, they aren't saying that it can't accomplish ends. They are saying it is wrong or bad.

OK but really, look over the paragraphs or my summaries of the paragraphs, and see which ones actually make points that the article uses to support its claim and which actually connects them to it.

It makes some attempt to make the reader more sympathetic to using violence to oppose trumpishness by pointing out the violence used by proponents of trump/trumpishness, but it does not actually say that this is a justification. Just that it is not surprising, or things like that. ( Seems like moral relativist / nihilist stuff. Moral relativism and moral nihilism can both go fall down a well.)

Now, some of the things that they say seem like good points, but none of these are things that actually justify using violence for a political cause.

It is true that trumpishness seems to reflect a cause or change in the overton window in a harmful direction.

But the thing about political norms of discourse, is that each group generally views its opponents views as being harmful! If everyone considered an opposing view being harmful to be sufficient to justify violence, then all groups would consider violence against all of their opponents to be justified! That would make for either a very violent political setting, or a setting where one group is sufficiently dominant, and likely not because that group is the one that is most correct.

I have already said that violence being "useful" is not enough to justify it.

The article is full of things along the lines of "even if you personally would not use violence [...] ". This reeks, or at least smells, of moral relativism. Moral relativism can go fall down a well.

Use of violence in a particular situation is either justified or it is not. If it is not justified in a certain situation, it does not matter if one "does not have the privilege to consider" whether violence is permissible. It either is or it isn't.

Further, if someone truly could not take the time, or whatever resource the author supposes they lack, to consider whether violence is justified, what possible harm would there be in someone else arguing that it is not justified? Either the oppressed person cannot consider the argument, and the argument has no bearing on them, or they can, and therefore they can consider it after all. I suppose the idea might be that the line of reasoning would cause other people to treat them in a harmful way, but, which people would do that? Who are the people who would be treating someone badly because they disaprove of that person's use of political violence? If it would be some large organization such as the police, or perhaps their boss at their work, I don't think that even the opposite argument instead of the one argument would cause these institutions to treat the person differently. Otherwise, what is the impact? If it is not the impact, is the author claiming that arguing against violence is inherently wrong even if it has no practical consequences? Surely this is not what they mean.

tl;dr2:

Author barely makes any arguments towards their point, the one they make are not any good. Author seems to define ethics based on oppression vs oppressed, etc.