This week we begin profiling Australia’s most influential Rich Crusaders, the people who use their cash to influence public debate and promote causes they believe in. Here, Paul Barry presents the shortlist.

Gina Rinehart

Money talks. And no one has more than Gina Rinehart, who is a billionaire 20 times over. But can she buy influence over two of Australia’s most famous newspapers, The Sydney Morning Herald and Melbourne’s The Age?

The Power Index reckons the answer is no — or not yet — despite her recent raid on Fairfax Media, which has left the mining magnate with 14% of the shares.

Gina thinks global warming is nonsense and the mining tax is a disgrace. Last year she jumped on the back of a truck with fellow billionaire Andrew Forrest, and led the chant to “Axe the Tax”. She also funded climate-change denier Lord Monckton’s recent Australian tour.

Graeme Wood

Greens donor, Global Mail bankroller and pulp mill buyer: Wood is trying to sway the debate his way

Graeme Wood isn’t half as rich as Gina Rinehart, but he’s trying hard to sway the debate. In 2010, he set an Australian record for political donations by giving the Greens $1.6 million for the TV ad campaign that helped win the balance of power in the Senate.

Nine months later, he laid out $10 million to buy Gunns’s Triabunna woodchip mill, so he could shut it down and end the logging of native forests in southern Tasmania. As you can guess, the locals love him.

His latest venture is the online (left-leaning) Global Mail, which he will bankroll for the next five years to the tune of $15 million.

Dick Smith

It’s a quarter of a century since Dick Smith was dubbed Australian of the Year, but at 68, the nation’s best-known boy scout is still agitating for the Australia he’d like to live in: where imports don’t bankrupt our farmers and the fragile environment is protected.

Dick’s been called a hypocrite, a pest, an egomaniac and a shameless self-promoter, (for stunts like going to the Melbourne Cup in a huge top hat advertising his own-brand OzEmite). But he’s gutsy, generous and passionate about making Australia a better place.

Andrew Forrest

Super salesman Andrew Forrest set up Fortescue Metals in 2003 and has made $5 billion, making him the third richest person in Australia.

With help from his fellow iron ore billionaire, Gina Rinehart, Twiggy led the crusade against the mining tax.

But that’s not his only political act. In 2008 he got prime minister Kevin Rudd to launch his Australian Employment Covenant, and roped in James Packer, Lindsay Fox and Kerry Stokes to support its pledge of 50,000 indigenous jobs. Twiggy has also given $130 million to charities in the past four years.

Rupert Murdoch

We thought we’d put him in, even if he doesn’t quite fit the definition, because no one is better than Rupert at using his money and power to influence the political debate. Murdoch’s 175 newspapers around the world were unanimous in supporting the invasion of Iraq in 2003, (once the Hobart Mercury was called into line), and over the years they have fallen in behind Ronald Reagan, Margaret Thatcher, Tony Blair and our own John Howard. Rupert even made and broke Gough Whitlam almost 40 years ago. But he’s already on our media moguls list and his political activism is more a business than a hobby. So he may not make the cut.

Read the full story at The Power Index.