Election campaigns are busy times for interest groups. They turn up the pressure on governments and oppositions to give them written promises to grant them particular benefits, or not do things the groups don't fancy, during the next term.
It's surprising how often the pollies give in to such tactics. They do so for fear the interest groups will campaign against them if they don't sign on the line.
In the last federal election, for instance, the banks and other financial institutions got the Labor government to promise not to make any more adverse changes to the taxation of superannuation for five years, then persuaded the Coalition to match Labor's promise during its first term. A lot of promises have been broken since then, but not this one.
Historically, few groups have pursued this tactic more successfully than the Catholic systemic schools. If you were a pollie, which would you choose: risk being preached against on the Sunday before election day, or be photographed beside a beaming archbishop as you sign the deal?
Recognising the Catholics' superior bargaining power, the other religious and independent schools tend to ride on their coat-tails.
Late last month the Catholic Education Commission announced that in the NSW election campaign it would "play an advocacy role in the interests of students, parents and teachers in the Catholic education sector".
Its "key policy issue" is that, in the light of the expected growth in the number of schoolchildren, the state government "must increase its capital funding to Catholic schools to help Catholic schools enrol their share of this growth".
Last year, we're told, the state's 584 Catholic schools educated 21 per cent of the state's students, but received only 2 per cent of the NSW government's capital funding for schools.
"The NSW Government must first reverse its 2012 decision to cap capital funding to non-government schools at $11 million per year and put in place a sustainable, long-term funding framework that grows as enrolments increase", the commission's executive director, Brian Croke, said.
The Catholic schools' share of the $11 million was $7.6 million, equivalent to about $30 per student, while government schools received more than $399 million, or $524 per student.
The state government's forecast is that all NSW schools will need to accommodate an extra 267,000 students by 2031. For the proportion of students in Catholic schools to remain unchanged, Catholic schools would need to create places for a further 58,000 students, the equivalent of more than 2300 new classrooms.
Sorry, but this argument needs thinking about. For one thing, the campaigners don't mention that non-government schools also receive capital funding from the federal government, which is a lot more generous than state grants.
For another, it's hardly surprising the state government spends a lot more on building and equipping its own schools than it does on subsidising other people's schools.
Where do taxpayers' obligations to Catholic and other non-government schools end? Governments have an obligation to provide for a growing student population, but do they have an obligation to ensure Catholic or any other non-government group's share of the school population doesn't decline as the population grows?
For religious or other groups to say they have school facilities they wish to make available for the education of kids - kids of their own choosing in locations of their own choosing - is one thing. For those groups to argue governments have an obligation to subsidise their provision of additional facilities so their share of the overall school population doesn't drop is quite another.
Who's to say those non-government groups will want to build their additional facilities in those locations where the population growth occurs? If the groups want to build in areas other than those of fastest growth - which these days would include the inner city - are taxpayers obliged still to cough up subsidies while also building the new schools where they're actually needed?
And is it reasonable to demand that taxpayers provide big subsidies towards the building of new facilities that remain the property of the churches or other groups involved?
The Catholics argue that their building of new facilities has been, and will continue to be, largely funded by parents. So the church itself doesn't put up much, but gets to retain ownership of the schools while the parents move on. When it comes to real estate, I wouldn't have thought the mainstream churches were all that property poor.
Federal grants come with a proviso that, should the subsidised school facilities be sold or used for another purpose within the first 20 years, the government may ask for its grants to be repaid. How often this provision is enforced I don't know.
We've long been asked to believe the non-government schools are doing taxpayers a favour, providing education to kids that taxpayers would otherwise have to pay for. But this demand for capital grants is aimed at reducing the size of the favour.
And when it comes to recurrent funding, the favour isn't all that great. Federal and state grants covered almost three-quarters of the costs of running Catholic schools in 2012. Fees charged to parents covered another 22 per cent.
With the election just a few days away, I'm hoping whichever side wins will get through without promising more funds to non-government schools. But we may not know whether they have until after it's over.