Meaning: Political terms. Right meaning conservative. Left meaning liberal.
Matthew 25:32-33
And before him shall be gathered all nations: and he shall separate them one from another, as a shepherd divideth his sheep from the goats: [33] And he shall set the sheep on his right hand, but the goats on the left.
It was a practice in some European assemblies to seat the honored nobles, who were more conservative, on the prefered right side of the hall. The less-esteemed and more revolutionary liberals were seated on the left.