Asklemmy

CIA?

The term "tankie" was originally used by dissident Marxist–Leninists to describe members of the Communist Party of Great Britain (CPGB) who followed the party line of the Communist Party of the Soviet Union (CPSU). Specifically, it was used to distinguish party members who spoke out in defense of the Soviet use of tanks to crush the Hungarian Revolution of 1956 and the 1968 Prague Spring uprising, or who more broadly adhered to pro-Soviet positions.

Seems pretty leftist to me. And it doesn't have any other baggage to it, like ableism, classism etc.

For contrast:

The term "nazi" had been in use, before the rise of the NSDAP, as a colloquial and derogatory word for a backwards farmer or peasant. It characterised an awkward and clumsy person, a yokel. In this sense, the word Nazi was a hypocorism of the German male name Igna(t)z... a common name at the time in Bavaria, the area from which the NSDAP emerged.

Which is a word I personally find very useful and will never stop using when appropriate.