They never learn that tax cuts can easily, post-election, be reversed, or be substituted for by increases in other charges and levies, and that all too often tax cuts benefit the wealthy first and the average taxpayer a long way back in second.
Most significantly, few pause to think of the price that will be paid tomorrow for the tax cuts they are promised today (assuming that they do in fact materialise as promised).
If the Government takes less in tax, the few dollars saved in each individual pay packet or weekly budget will, when multiplied many times over, mean reduced spending (usually called cuts) in providing essential services on which a civilised, healthy, happy and economically productive society depends.
I could not help but be struck last week on hearing - on a perfectly ordinary day for news - about two further instances of the wearyingly familiar theme of how cuts mean that we are, in large numbers, worse off than we should be.
First, family doctors pointed out that increasing numbers could not afford to see the doctor when they are sick, because the funding for primary care is inadequate.
And school principals complained that their low level of funding made it impossible to maintain appropriate levels of trained staff to teach our children.
A moment's thought would convince most people that underfunding our children's health and education in this way is not a sensible way of building our future and they would recognise that this is the inevitable consequence of cutting back on essential public spending - yet those same people would happily fall for the bait they are offered when tax cuts are dangled in front of them.
And that is to say nothing of other cuts, right across the board - cuts in essential services such as defence, or law and order, or biosecurity, or in investments in our future capabilities - that make us less secure, less fair, less integrated and less productive.
That may be bad enough, but this is a dynamic, not a static, situation.
The offer of tax cuts tells us about both the future and the past.
It tells us that the Government has taken more from us in tax over recent times than it turned out to need - that, according to its own calculations at any rate, it can give back some of the tax it took from us.
What parades as an apparent act of generosity is, in other words, merely a confession of past miscalculation - one that cost us dearly in reduced public services.
But it also tells us that the Government has learnt no lessons from the inevitable downsides of its policies.
It is still prepared to gamble with our future and to preside over a country that is weaker, less united and less able to face the future than it need be - and all for the sake of gaining a few more votes from those who can be bamboozled.
The lesson should be clear. Tax cuts are bought at the cost of worse public services - and worse public services (or cuts) mean that the price we all pay is a heavy one, not least for those least able to afford it.
Bryan Gould is a former British MP and Waikato University Vice-Chancellor.
