I can think of a few ways we can reduce the degree of squabbling to a minimum:
Favour quantitative questions over qualitative
Whilst a quantitative question can be bent towards partisan goals (lies, damned lies and statistics); qualitative questions are far more prone to this problem in both the question and subsequent answers. Qualitative questions are often more fun (a key survival requirement for a beta stack exchange) but need to be very well described as even an errant word or turn of phase can turn these types of questions in a political conflagration.
Trim anecdotes, partisan website excerpts and author commentary from question
If the question feels like a statement instead of a question, especially if the statement comes in the form of supplementary material not needed to ask the question - remove the content from the question. If that leaves nothing left; then the question can be closed as not actually asking anything.
Swiftly migrate any economic policy questions to the Politics stack exchange
A question about the current policy platform of a party, past or present, is a political question - as are questions asking if a given political act follows one economic model or another (communist, capitalist, etc). Migrate these to the Politics stack exchange, as that stack is already infested with partisan bickering.
An economics stack exchange should only be concerned with questions about understanding an economic school or how an past or future event would be interpreted by an economic school. Not those questions that just want a confirmation that an political act or a country exemplifies an economic school of thought, or a pop-culture caricature of such.
Make use of the duplicate question feature
If and when we can't avoid political questions, we can starve them of oxygen by only answering the question once and then routing all future duplicates. Participants that only want to ask or answer politically charged topics will run out of steam when they have no space to emote as the topic has been already been asked, answered and frozen before they arrived. Stringently clearing comments from duplicates will also mean the political trolls will exhaust themselves and their commentary within a few old questions we can periodically mop up.
Questions asking for value judgements must specify from what economic school(s)
Questions asking for value judgements will pop up in both blatant and subtle forms. Questions that haven't specified which economic school is to interpret the data and provide the value judgement, the moderators should prompt the OPs to provide (perhaps from a standard menu of common models/schools).
If OP has no preference or there is has been no reply, moderators should amend the question with "as interpreted by particular economic schools of thought". This serves to reduce political squabbling within each answer, as the value-judgements are contextualised and separated across multiple answers (to be voted by depth and data, not "coolest school")
Questions asking to compare the relative merits of economic schools are either answered only once on the site very well or never on the site
Unless a person is asking about the specific scientific or logical rigour of an economic school or model, which they almost never are, a question about relative merits is pointlessly orthogonal as it just resolves to axiomatic predicates of a political, sociological and emotive nature. So a thunder-dome cage-match is unhealthy and out of scope for an economics stack exchange. Either answer only once on the site and very well, or ruthlessly shoot down any questions asking for this type of comparative political ranking of economic models.