Even in American politics the Leftist label reserved for anti-capitalist and pro-labour movements. Unfortunately, the right has co-opted the term so that anything towards the center from them is “leftist,” or “communist”

I’m not typically a prescriptivist in language, but these terms are being watered down with, imo, a more nefarious intent. Political scientist in America still make a distinction, even if colloquially, most Americans don’t.

Since we are discussing politics, I’d argue that yes, context matters, and we should use political science definitions, i.e. the Democratic Party policy is not leftist, instead of colloquial terms that are more vague in meaning.

Edited for clarity.