Who should pay for political advocacy?

I asked the question yesterday, how come an advocacy outfit like the Child Poverty Action Group retains charity status while an advocacy outfit like Family First loses theirs?

Simon Collins is doing pretty much the same in the NZ Herald and has listed a few others.

It seems to me that either all political advocates should get charitable status, or none. There are plenty of taxpayer funded political advocates like the Families Commission and the Children's Commissioner. We have no choice about 'donating' to these lobbyists. So perhaps it could be argued that we should also be able to easily donate (meaning get a rebate) to groups who represent our own particular viewpoint.

But then why shouldn't other commercial interest representative groups also claim charity status? Outfits like Federated Farmers or Business New Zealand? Their members pay for political advocacy on their behalf. But I am forgetting. They are about profit, and profit and political advocacy should never be mentioned in the same sentence.

(For the record I've never solicited donations to do my welfare reform advocacy, as low profile as it is. In fact, it costs me.)

The underlying problem is the size of government. If it didn't pretty much monopolise spending in the social sphere,  there would be no need for the degree of political pleading that goes on.