In his thirty years on the Supreme Court, Justice Antonin Scalia relished being the centre of attention, so he would no doubt take some satisfaction in knowing that the timing of his death last week has profoundly altered the course of this presidential election. The stakes are higher, the choice stark.

The bitter dispute over the President’s right to nominate a successor that erupted within hours of his passing is a reminder that in the United States of America, the judiciary is as politicised as any other branch of government.

Revered by conservatives and despised by liberals, Scalia was renowned for writing opinions that courted controversy. In one dissent, he equated homosexuality with bestiality and murder. In a recent hearing he suggested that most black students might be better off in “slower-track” colleges. He once pointed out that providing he has had a fair trial, nothing in the US Constitution prohibits the execution of an innocent man.

"The death penalty? Give me a break. It's easy. Abortion? Absolutely easy. Nobody ever thought the Constitution prevented restrictions on abortion,” he told an audience at the right-wing American Enterprise Institute last October. “Homosexual sodomy? Come on. For two hundred years, it was criminal in every state.”

Scalia’s ‘originalist’ reading of the Constitution twisted the meaning of the USA’s founding document to support modern conservative principles. He didn’t always prevail, but he drove the Supreme Court to the right as it struck down gun-control laws, weakened environmental regulation and permitted billionaires to spend as much as they please to influence elections.

Republican presidential candidate Ted Cruz, who as Solicitor General of Texas argued nine cases before the Supreme Court, wasted no time in framing the election as a battle to choose Scalia’s successor. On the campaign trail in South Carolina, he warned that if a Democratic president is able to reshape the court, gun rights will be curtailed and “unlimited abortion on demand” will become the law of the land. “Two branches of government are at stake,” he said.

Notwithstanding the fact that Article II of the Constitution grants the current President, Barack Obama, the right to nominate a judge to fill the vacancy, Cruz’s broader point is right. Justice Ruth Bader Ginsburg is eighty-two and has had two battles with cancer. Justice Anthony Kennedy is seventy-nine and Justice Stephen Breyer seventy-seven. Even if the Republican-controlled Congress approves Obama’s nominee to succeed Scalia (which appears unlikely, to say the least) the next President will probably appoint two or three Supreme Court judges.

In 2013, retired Justice Sandra Day O’Connor warned that “if Americans start thinking of judges as politicians in robes, our democracy is in trouble.” She was too late. In polls, when people are asked whether they believe that Supreme Court justices base their decisions on the law or on own their personal and political views, fewer than one in four trust judges to be free of bias.

The day Scalia died, partisans on both sides abandoned all pretence of supporting judicial independence. Five minutes after the San Antonio Express broke the news, Conn Carroll, the communications director for Republican Senator Mike Lee, tweeted: “What is less than zero? The chances of Obama successfully appointing a Supreme Court Justice to replace Scalia?”

Senate Majority Leader Mitch McConnell, also Republican, issued a statement: “The American people should have a voice in the selection of their next Supreme Court Justice. Therefore, this vacancy should not be filled until we have a new President.” There is no historical basis for this - of the thirteen Supreme Court vacancies that have arisen in the last year of a President’s term in office, eleven were filled.

Donald Trump suggested that “delay, delay, delay” would be a wise tactic for Republicans to adopt. Across the map, the Republican Party’s candidates chipped in with promises to obstruct any Obama nominee, ignoring both precedent and the letter of the Constitution.

On the fringes, conspiracy theories bloomed like algae. Trump was asked by right wing radio host Michael Savage, who has around five million daily listeners, whether he thought Scalia had been murdered. “They say they found a pillow on his face, which is a pretty unusual place to find a pillow,” Trump replied.

Obama will nominate a justice once the Senate returns on February 22. “The Constitution is pretty clear about what is supposed to happen now,” he said at a press conference in California. “There’s no unwritten law that says that it can only be done on off years (years in which elections tend not to be held for Federal offices).”

Some Democrats could not resist gloating. David Plouffe, Obama’s former strategist, suggested that Republican party’s immediate threat to obstruct the nomination “might just have ensured the Obama coalition turns out in 16,” adding “Dem WH [White House] for 16 straight years, Dem Senate in ’17. Geniuses.”

Who will Obama nominate? The bookies favourite is Sri Srinivasan, an Indian-American jurist who was unanimously confirmed to an Appeals Court position by the Senate less than three years ago. The more aggressive choice would be Attorney General Loretta Lynch, who would be the first African-American woman on the Supreme Court. The inevitably nasty, drawn-out effort to block her appointment could drive up Democratic turnout in November’s election.

In the 2000 presidential election, Scalia was part of the Supreme Court majority that stopped the recount in Florida, handing George W. Bush the keys to the White House. When challenged about this, Scalia had a stock response: “Get over it.” But while this was surely his most infamous vote, his most consequential was in Citizens United v Federal Election Commission, the cornerstone of a political system in which money can buy elections without any laws being broken.

Citizens United is one of five associated rulings loosening campaign finance restrictions passed by the Supreme Court on the basis that political donations are free speech, protected by the First Amendment. There is now effectively no limit to how much an individual or company can spend.

Most money is paid into so-called Super PACs. These may advocate on a candidate’s behalf, but are legally prohibited from co-ordinating their actions with the official campaign, a distinction so weak, and so weakly enforced, as to be a running joke.

Every candidate has one, with the exception of Donald Trump and Bernie Sanders: Right To Rise for Jeb Bush, Keep The Promise for Ted Cruz, Conservative Solutions for Marco Rubio and Priorities USA Action for Hillary Clinton. Bush raised $100 million for his before he even publicly declared that he was in the running.

The Citizens United ruling also empowered people and corporations that want to influence political outcomes without being seen to do so. ‘Dark money’ groups are not obliged to disclose the identity of donors. They may only support a cause, rather than a specific candidate, but again, this distinction is meaningless in practice, when they can pay for attack ads against a rival.

In the ten most competitive races of the 2014 midterm elections, 70% of the money behind the winning candidates came from undisclosed sources. Voter turnout was the lowest it has been since World War Two. As Justice Breyer warned in his dissent to a ruling that abolished contribution limits: “Where enough money calls the tune, the general public will not be heard . . . And a cynical public can lose interest in political participation altogether.”

In October, the New York Times reported that just 158 families were responsible for $176 million of political donations in this election cycle. Unsurprisingly, as most made their money in the banking and energy sectors, 138 of them backed Republican candidates that favoured looser financial and environmental regulation and lower taxes on the wealthy.

This is the era of the mega-donor: casino magnate Sheldon Adelson, fracking tycoons the Wilks brothers, hedge fund managers Tom Steyer and Robert Mercer, media magnate Haim Saban and Hank Greenberg, the former Chief Executive of AIG insurance. These men are not well known to voters, but they wield an outsized influence, thanks to their willingness to spend millions of their billion-dollar fortunes on getting their preferred candidates elected.

The billionaire Koch Brothers, Charles and David, have built a national network of donors and pressure groups promoting “pro-business” policies. They have promised to spend $900 million this election cycle.

So far, Greenberg is responsible for the biggest single donation: $10 million to Jeb Bush’s Right To Rise. Eight years ago, brother George Jnr’s Treasury Department bailed out AIG with $182 billion of taxpayer money, so that it could make good on its catastrophically bad bets with the banks. This is how political influence works. The Supreme Court has ruled that only a favour done in return for money - “quid pro quo” - constitutes corruption.

Tough as it may be to hear, but it was Donald Trump who put it best at the first Republican debate. Surveying his rivals lined up along the stage, he claimed to have donated to almost all of their campaigns at some point. “I give to everybody. When they call, I give,” he said. “And you know what? When I need something from them, two years later, three years later, I call them, and they are there for me. And that’s a broken system.”

It is ironic that the “broken system” that has unleashed unprecedented spending, electing Senators and Congressmen beholden to their wealthy patrons, has also produced two leading presidential candidates that decline big donations entirely. They are playing to very different crowds, but by refusing to accept money from banks and corporations, Trump and Bernie Sanders have tapped into the same deep unease that the USA is becoming a plutocracy - a nation run by the biggest of big business.

Trump reminds his supporters that Cruz is dependent on the financial sector: “Goldman Sachs owns him. Remember that, folks. They own him.” In reference to Bush, he asks: “What does $100 million mean? $100 million means he's doing favours for so many people.”

In his victory speech after winning the New Hampshire primary, Sanders appealed to the small donors that have bankrolled his campaign. “I'm going to hold a fundraiser right here, right now, across America,” he told the crowd. “Please help us raise the funds we need, whether it's ten bucks, twenty bucks, or fifty bucks.” By the following afternoon, his campaign had raised an additional $5.6 million. The average donation was $34.

His rival Hillary Clinton has also stressed the need to reform campaign finance, but it has been a little harder for her to make the case since hedge fund manager George Soros donated $6 million to her Super PAC.

Between now and November, candidates and their surrogates will spend an estimated $6 billion on television advertising. As election day approaches, more and more of this will be ‘dark money’ paying for attack ads on behalf of groups with inspiring names like Americans For Prosperity, Citizens for Sound Government and the American Future Fund. Antonin Scalia is dead, but the system he helped create, in which judges are nakedly partisan and billionaires wield untold political influence, is alive and well.