And the nation's billionaires are already responding enthusiastically.

The Koch brothers, energy and chemicals magnates with an estimated fortune of over $A100 billion and a serious aversion to environmental and labour regulations, have already declared they will spend $A1.2 billion on their pet state, congressional and White House candidates.

These circumstances, says Fred Wertheimer​, a Washington DC lawyer and lobbyist and one of America's leading campaigners for campaign finance reform, are unheard of  and are going to have a seriously damaging affect of  the country's democracy.

Under the changes to campaign finance laws prompted by a Supreme Court decision known as Citizens United, individuals, unions and businesses were freed to spend as much as they liked on political advocacy, with the conservative majority of the court reasoning that companies, like people, had rights to freedom of speech, and spending money on a political cause was a form of speech in itself.

This meant that while limits on donations to candidates remained in place, anyone or any group could donate as much as they liked to a group formed with the express purpose of having that candidate elected.

These groups became known as super PACs (political action committees).

Under such regulations anyone can donate as much as they want to, say, Right to Rise, which was created by Jeb Bush with the sole purpose of electing Jeb Bush. By comparison, Bush's own campaign may accept only $US5400 per donor.

The only caveat is that the super PACs have to remain independent of the campaign.

This change prompted a surge of political spending by mega-donors, which in turn prompted increased spending via other mechanisms. People started pumping money into vehicles that were technically charities, but charities concerned entirely with electing candidates.

These are known as 501 (c) (4) organisations, after a clause in the tax code. They are completely tax exempt, and - even better for the publicity-shy billionaire keen to make a political statement - donors to them can remain utterly anonymous.

To illustrate how the new rules are affecting politics this election cycle, Ken Vogel, a journalist with Politico and the author of a book on the new campaign finance laws called Big Money, cites Marco Rubio​'s campaign.

So far this election cycle Senator Rubio's official campaign has raised just $US13 million. But his super PAC has raised another $US15 million and his 501 (c) (4) has voluntarily disclosed donations of $US15.8 million.

Mr Bush's campaign has raised just $US11.4 million, but his super PAC has raised a staggering $US103 million.

This makes the super PACs the new power players in presidential campaigning. Their directors arguably have more control than even the campaign directors. And the ban on coordination between super PACs and campaigns has proved to be farcical.

Earlier this year, Mr Bush simply delayed formally announcing his candidacy for a few months so he could spend that extra time running - and fundraising for - Right to Rise.

In the end, says Mr Wertheimer, it does not really matter what the donors want now, or why they are spending their money. What matters is what they will want after the winners take their seats, and the billionaires pick up the phone.