The terms left wing and right wing originated in the French National Assembly in 1789. 

On the right side of the chamber sat the Conservatives who supported the monarchy, the established church, and the existing hierarchy.

On the left side of the assembly sat the Radicals who were in favor of a revolution and serious reforms.

When the terms leapt across the pond to America the right wing was the Conservatives and Republicans.

The left wing was the Liberals and Democrats.

I don't believe these designations are very useful any longer.

Instead we need to bifurcate politics into the 'Totalitarians' and the 'Libertarians'. 

While these designations are not perfect they are far more accurate today than those which proceeded them.

Also, this calls attention to the fact that the totalitarian impulse crosses political boundaries and exhibits itself on both sides of the aisle. Although, I believe a strong case can be made that the majority of the totalitarians of this generation are left of center, to fall back somewhat upon the the outdated left right divide.