Tankie's original use was for British communists who supported Soviet military expansion. In the modern sense, it is used to describe communists who are authoritarian-apologists. For example, a communist who romanticizes the Soviet Union or makes excuses for the Uyghur genocide is a tankie. I've also seen it stretched to include militant anti-capitalists, or more commonly, "militant," anti-capitalists who call for violent resistance to capitalism from the safety of a keyboard.
Democratic-Socialists are not tankies. Socialists are not tankies. I don't even think most communists qualify as tankies. Criticizing Democrats does not make you a tankie. Condemning Israel's human rights violations does not make you a tankie. Voting third party doesn't make you a tankie. I see this term used here every day, but never correctly.
Yeah, to be clear, I'm not saying that tankie should only be used for British communists that supported sending tanks into Hungary. I think the definition you just gave is the correct modern usage, that's why I included it in the post, and even though I think using it to mean, "communists who are violently anti-capitalist but only online and never IRL," is a stretch, I'm not gonna correct anyone saying it. But go ahead and look at the biggest/most controversial posts of the last week, CTRL-F, "tankie," and see what you get. I'm willing to bet its someone getting called a tankie for criticizing Biden or the Democrats, not defending authoritarian-communist regimes.
I'm sure the biggest offenders will keep misusing the word, but I'm hoping at least some people will see this post and go, "Oh, damn, I've been using that word wrong. Oops." Then they'll probably downvote me anyway, but hopefully they'll stop misusing the word, if for no other reason than the fear of looking dumb.
I think it's fairly likely that a lot of anti-leftist people online just happened to learn the word this year, and they're excited to use it.
Yeah, that tracks, I've seen it get used a lot more in the last six months to a year. Some boomer must have used in in their Facebook group.