OPINION: Will Turnbull prove a big spender?

The past 40 years in Australian politics has shown that prime ministers have little more than a term to enact any sweeping policy changes.

After that, their political capital runs dry and life in The Lodge becomes a dog fight to win the next election.

Gough Whitlam, Malcolm Fraser, Bob Hawke and John Howard were all elected with the right combination of a strong majority of seats and popular support to allow them to make real changes to our nation.

Whitlam opened universities to the masses, Fraser turned off the government spending tap, Hawke restructured labour laws and floated the dollar, and Howard introduced gun control and the GST. But what they all had in common was that they acted quickly and spent their political capital wisely.

Kevin Rudd, another PM swept to power on a wave of support, spent his political capital on an apology to the Stolen Generation and signing the Kyoto Protocol, only to find the kitty was empty when he tried to introduce an emissions trading scheme.

Which brings us to Malcolm Turnbull.

Mr Turnbull has not been swept to power by the people but, rather, a nervous backbench within his own government, yet he is riding high in all published polls at the moment.

That has given him the courage to openly canvass an increase to the GST – the sort of potentially unpopular policy that could sink a leader who was already struggling in the polls.

Sensibly, he is acting quickly while his numbers still look good, but going to an election with a policy of a 15 per cent GST might truly test the depth of that support.

If this is how Mr Turnbull plans to gamble his political capital, then only time will tell if it is a wise investment.