Pre-Revolution Trot supported Socialism, though he hitched himself to the Menshevik - who wanted a more peaceful and slower progress into Socialism. That party was mostly occupied by Social-Democrats and Liberals, and would side with the Whites during the civil war. After Trot left the Menshevik, he would tack himself onto other people’s ideals and act as an opportunist. More or less everything he’s credited for during that time was the brainchildren of other people, including the theory of the permanent revolution, to which would have crushed the Union. After Lenin died and Stalin took power, Trot started moving quickly to the right. During the leadup to the second world war, he would be escorted through Fascist Italy via Italian officials, and he would be preparing to go in front of the House of Un-American Activities Community before his assassination.

Or to sum, Trot was an opportunist who turned his back on the revolution. And, worst of all, the bigger group of his supporters completely whitewash his theories to be anti-Communist and anti-Stalin, so now - at least in the west - his memory is and can only be synonymous with Anti-Communist Leftism.

I do recommend reading Trot’s works though, he does have some genuinely good theory. And if you’re looking for Trot orgs that are half-decent, it’s best to look outside of the west.