To watch American politics today is to watch money speaking. The 2016 US elections will almost certainly be the most expensive in recent history, with total campaign expenditure exceeding the estimated $7bn (£4.6bn) splurged on the 2012 presidential and congressional contests. Donald Trump is at once the personification of this and the exception that proves the rule because – as he keeps trumpeting – at least it’s his own money. Everyone else depends on other people’s, most of it now channelled through outside groups such as “Super PACs” – political action committees – which are allowed to raise unlimited amounts from individuals and corporations.

The sums involved dwarf those in any other mature democracy. Already, during the first half of 2015, $400m has been raised, although the elections are not till next autumn. Spending on television advertising is currently projected to reach $4.4bn over the whole campaign. For comparison, all candidates and parties in Britain’s 2010 election spent less than £46m. In Canada’s recent general election the law allowed parties to lay out a maximum of about C$25m (£12.5m) for the first 37 days of an election campaign, plus an extra C$685,185 (to be precise) for each subsequent day.

Rejecting a challenge to such campaign finance regulation back in 2004, the Canadian supreme court argued that “individuals should have an equal opportunity to participate in the electoral process”, and that “wealth is the main obstacle to equal participation”. “Where those having access to the most resources monopolise the election discourse,” it explained, “their opponents will be deprived of a reasonable opportunity to speak and be heard.”

The US supreme court has taken a very different view. In its 2010 Citizens United judgment it said, in effect, that money has a right to speak. Specifically, it affirmed that a “prohibition on corporate independent expenditures is … a ban on speech”. As the legal scholar Robert Post writes, in a persuasive demolition of the court’s reasoning, “this passage flatly equates the first amendment rights of ordinary commercial corporations with those of natural persons”. (Or, as the former presidential candidate Mitt Romney put it in response to a heckler: “Corporations are people, my friend,”)

In a book entitled Citizens Divided, Post demonstrates how the Citizens United judgment misunderstands the spirit and deeper purpose of the first amendment: for people to be best equipped to govern themselves they need not just the freedom of political speech, but also the “representative integrity” of the electoral process.

Of course, an outsize role for money in US politics is nothing new. Henry George, one of the most popular political economists of his day, wrote in 1883 that “popular government must be a sham and a fraud” so long as “elections are to be gained by the use of money, and cannot be gained without it”. Whether today’s elections are so easily to be gained by the use of money is doubtful, when so much of it is sloshing about behind so many candidates, but does anyone doubt the “cannot be gained without it”?

Money may have been shaping US politics for some time, but what is new is the scale and unconstrained character of the spending, since the 2010 Citizens United decision and the Super PACs that it (and a subsequent case in a lower court) enabled. Figures from the Center for Responsive Politics show outside spending in presidential campaign years rising significantly in 2004 and 2008 but then nearly trebling in 2012 – and, current trends suggest, we ain’t seen nothing yet.

The American political historian Doris Kearns Godwin argues that the proliferation of Republican presidential candidates, so many that they won’t even fit on the stage for one television debate, is at least partly a result of the ease with which wealthy individuals and businesses can take a punt on their own man – or Carly Fiorina. A New York Times analysis found that around 130 families and their businesses accounted for more than half the money raised by Republican candidates and their Super PACs up to the middle of this year. (Things aren’t much better on the Democrat side.) And Godwin urges her fellow citizens to “fight for an amendment to undo Citizens United”.

The Harvard law professor and internet guru Larry Lessig has gone a step further, himself standing for president on the single issue of cleaning up US politics, with a draft citizen equality act covering voter registration, gerrymandering, changing the voting system and reforming campaign finance. That modest goal achieved, he will resign and hand over the reins to his vice-president. Earlier this year he said he would proceed if he managed to crowdfund more than $1m, which he has done. Not peanuts for you or me, but Jeb Bush’s Super PAC, Right to Rise, is planning to spend $37m on television ads before the end of February next year. So one of the problems of the campaign for campaign finance reform is … how to finance its campaign.

If you read the Guardian, or watch(ed) The Daily Show with Jon Stewart, or the Sunday morning GPS programme with Fareed Zakaria, or generally cruise around the online media, you will be well aware of Lessig’s civic crusade. But if you watch American politics in the ways most Americans do, you probably won’t have a clue. Online civic mobilisation versus $4.4bn for television ads? It worked to stop a couple of bad intellectual property bills, the Stop Online Piracy Act (Sopa) and Protect Intellectual Property Act (Pipa), but that was table tennis compared with this bruising game of American football.

So I don’t think it will happen this time, but that’s no reason to stop trying. Winston Churchill famously observed that you can rely on the Americans to do the right thing, once they have exhausted all the alternatives.

There is still some exhausting to be done: my guess is that it will get worse next year, and perhaps again in 2020, before it gets better. But awareness of the damage that the excessive influence of money is doing to the core democratic good of “representative integrity” is already seeping into the mainstream. The day will come, and let it be soon. It’s not only Americans who have a stake in the health of American democracy.