Las Vegas Sands chairman and chief executive Sheldon Adelson. (Ethan Miller/Getty Images)
Opinion writer

The Republican presidential candidates are set to crucify each other on crosses of gold.

GOP leaders exulted a few years ago when the Supreme Court’s Citizens United ruling and other decisions invited the rich to pour unlimited sums into political campaigns — and they are, by the billions of dollars.

But the Law of Unintended Consequences frequently rules the practice of politics, and it has once again. Republican candidates are hauling in so much money that the flood of cash has washed away the Darwinian system of natural selection that previously allowed parties to pick their nominees.

In the past, there was a money primary: If candidates polled poorly, their fundraising would dry up and they’d have to drop out of the race. But such market principles no longer apply, because a large number of inviable candidates are artificially subsidized — kept in the race by a beneficent billionaire, or even a friendly multimillionaire or two. With no easy way to push weak candidates from the race, Republicans are being hoist by their own gilded petard.

My Post colleagues Matea Gold and Ed O’Keefe reported Monday that no fewer than 15 White House hopefuls are being assisted by outside groups typically formed as “super PACs” and run by the candidate’s allies. For the first time in the modern political era, political operatives say it’s possible the eventual nominee need not win in either Iowa or New Hampshire.

Still-undeclared candidate Jeb Bush, who is on course to haul in $100 million by the end of next month, boasted to donors Sunday night that his fundraising has been historic (so good that his too-successful super PAC temporarily limited contributions to $1 million). But Bush’s take, Gold and O’Keefe noted, hasn’t stopped groups from raising, in short order, $20 million or $30 million apiece for Ted Cruz, Scott Walker and Marco Rubio. With that kind of money available, you’re unlikely to quit even if you’re an asterisk in the polls.

The outright acquisition of the primary process by the wealthy is the latest instance of the 1 percent taking over the American political system – although in this case it’s more likely the top 1 percent of the top 1 percent. As the Center for Responsive Politics notes, the top 1 percent of donors to super PACS (about 100 people and their spouses) contributed 67 percent of super-PAC funds in 2012.

Fred Wertheimer, a campaign-finance reformer who runs the group Democracy 21, predicts that, for the first time, spending by super PACs will exceed spending by candidates and parties combined in the 2016 presidential campaign, which is expected to cost some $5 billion.

In the 2012 primary, billionaire Sheldon Adelson’s money kept Newt Gingrich in the race long after he was a viable candidate (if he ever was). But if billionaires reached the moon in 2012, “this election will take us to Mars,” Wertheimer says. “We have a political system that is pre-Watergate and allows relatively few people to keep candidates in the race for extended periods of time. It’s going to create artificial candidates. . . . It’s going to open the door for influence-buying and corruption, and we have the Supreme Court to thank for that.”

Technically, candidates can’t coordinate with their super PACs, but the restriction is all but ignored. Bush is reportedly planning to use his super PAC to conduct operations that had traditionally been handled by candidate campaigns.

The Wild West nature of campaign finance would undoubtedly have a similar effect on the Democratic side if Hillary Clinton were facing a serious challenge. As it is, the anything-goes fundraising of Clinton and her husband has become a problem for the Democratic front-runner.

In recent days, her campaign has been dogged by reports that the Clinton Foundation took money from foreign governments and entities that stood to benefit from decisions made by Hillary Clinton’s State Department. The foundation admits it didn’t account for the contributions properly in tax filings. And, as The Post’s Rosalind Helderman reported, many donors to the foundation also paid Bill Clinton to give speeches — enriching the Clintons personally.

But Republicans, before they can exploit Hillary Clinton’s financial vulnerabilities in the general election, have to resolve a predicament in their primaries that once would have seemed enviable: Is it possible to raise too much money? As the likes of the Kochs and Adelsons sponsor candidates the way Medicis patronized Renaissance artists, there’s a real chance voters, particularly in early primary states, will lose their traditional ability to shape the field.

Thanks to the Roberts court, the sacred concept of one man, one vote has been replaced by a new reality: one billionaire, one ballot.

Twitter: @Milbank

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