There cannot be rigorous arguments in that sort of subject.
Called it.
Maintaining your belief requires you to preemptively deny the possibility of being wrong, just like any other religion.
Quite the contrary. Believing that your belief is certain and objective, rather than just probable and subjective, is the mark of religion.
There can't be rigorous arguments in economics or other "soft sciences". It is pointless to debate if we start disagreeing right there...
(Haven't you never read priests, politicians, and assorted pundits "prove rigorously" all sort of weird and contradictory ideas, from creationism to communism to why gun control is good/bad and beyond? Why do you think that those sciences are called "soft"?)
Agreeing with Sr. Stolfo here. Economics, politics, etc. are at least partially based on an individual's set of preferences. Arguing which of those sets is superior to another won't work unless you appeal to a set of higher axioms, which eventually always turn out to be ideologically motivated.
That said, there is
one case in which a rigorous political/economical argument can be made: in showing that one's set of preferences is contradictory.
However, the problem is that even in those potentially rigorous arguments, one will need to make some assumptions that are not easily seen as "objective", so we're back to the first point - that economical/political objectivity doesn't practically exist.