Mostly from the conservative side I'm sure.
No, equally from both sides, since both liberals and conservatives in the US tend to discuss issues such as religion, abortion, gun control, the death penalty etc. as being on a left/right axis, while if you define the left/right divde in purely economic terms these issues are purely tangential.
Meaning Marxist terms.
No, because the same terminology is used by right-leaning people. I think you may have misunderstood me, as this is a fairly value neutral concept. 'Left' refers to redistributive economic policies, and 'right' to economic liberalism.