Describing Trotskyism makes me go on and on and on so I will try to be as concise as I can.

The simplest summary is that Trotskyism defines itself through its opposition to Marxism-Leninism. It says, “we are communists, but not like them”. They actually hate us actively, we barely pay attention to them most of the time.

But the definition of Trotskyism through what they are not, and in particular, through their rejection of the major socialist revolutionary states of the 20th century (USSR and then China), they have a number of specific deficiencies that make them harmful:

• Trotskyists have the ultra tendency of criticizing every existing socialist project directly to liberals. This strategy is the “we should do socialism, but you should feel good in your fear and rejection of every socialist project”. Unsurprisingly they are often tailist as well. This also doesn’t work very well to actually organize their own socialist project.
• They are highly dogmatic in their idea of what tactics work and should be relied on based on the specific conditions of the Russian Empire and what they believe Trotsky did. namely, a focus on always believing in the revolutionary capacity of workers. In all situations regardless of context.
• Their concept of international solidarity is therefore twisted. It is often identical to imperialist aims, like supporting “resistance” movements in socialist-run states. They were and generally continue to be big believers in the capacity of the Zionist working class to overthrow the apartheid regime and end Zionism. They cannot fathom that their working class is enjoined to the project itself, they are too formulaic for this and have enjoyed being wrong on this for 80+ years. A book that has been shared here on socialist understanding of Palestine is actually Trotskyist and says these things.
• They have a splitting tendency. Their ideology is premised on hypercriticism and rejection and making a huge deal out of differences, right down to disagreements on tactics or individual positions on whether a campaign is going well. Sometimes a split is needed because the dividing line is important. This is rarely true with Trotskyists.
• They have an entryist tendency. A lot of what they do is trying to be “sneaky”, to oretetoto agree with others when they really do not, and they usually are not very convincing about the act. A given entryist project will look like five of them joining a space, seemingly independently, and they are clearly following a script to agree with each other on whatever topic they decided to push a point on. They also tend to be strident. They are bad at althis, so people notice quickly and say, “what the hell is going on? Who are these weirdos?” The result tends to be drama and a rejection of socialists from the space. The liberals don’t understand the differences between socialists, they just get a bad taste in their mouths. Our job of working in these spaces is already difficult and Trots make it harder.
• They do tend to form insular groups, which is understandable for communists, but unfortunately they are rarely internally healthy. I’ve never heard of a Trotskyist org that didn’t use a mentor system, where new members are closely monitored by an individual veteran member. Because they are insular, you don’t hear if the abuses from current members (they would be expelled), you only hear of them from ex-members and when there are dramatic splits and orgs break down. I also haven’t seen a Trot org where ex-members weren’t shunned. So young people tend to make some of their best friends in the org and then either live in fear of losing all their friends if they leave or are surprised when this happens.
• Speaking of young people Trotskyists are often active on college campuses and their orientation towards young people tends to be highly cynical, they are treated as expendable. They are again thinking dogmatically, they think fomenting student protests and so on will supplement their other world-historical projects of handing out newsletters nobody reads and pissing off workers at their workplaces. But combine this with the insular and often abusive tendencies and you get abuse from older members towards younger, in all its forms.

It should not be surprising then that theare have been no Trotskyist revolutions. The centrality if rejecting Marxism-Leninism leads them to self-destructive tendencies and an inability to understand the nature of the states in which they operate, like how to organize their working class, how to prioritize, how to message, how to internally organize and educate.