So it seems for most people, the term "racism" does not refer to privilege + power; e.g., those not in power can still be racist.
I think the privilege+power people should use a different word from racism so this is less confusing.
You cannot legitimately won arguments by simply redefining words. In any case, people should not be using the word racism. For anything. It’s entire framing now is specious. If there’s something you want to say and you’re tempted to use that word, do not. Find other words.
Racial prejudice by itself is racism. The power dimension can make one act on racism, and it is actions which are of concern as stopping prejudice would be illiberal. Power ofcourse isn't just systemic one way, and can manifest differently in different contexts.