If any lingering doubts remained, Tuesday should have erased them all. Republicans will weaponize anything – even in-person voting during a deadly pandemic – to maintain power, avoid accountability and bend electoral rules in their favor. Worse, the US supreme court will have their back.

Make no mistake: the deliberate chaos and unthinkable images from Wisconsin on Tuesday – Americans on line for hours, wearing homemade masks, risking a gruesome respiratory disease to exercise their right to vote – wasn’t just a warning sign for November’s elections. It was Republicans’ dress rehearsal.

It’s scarcely 200 days until the real show. The coronavirus has already pushed more than a dozen states to postpone primaries and forced fearful Ohio and Wisconsin governors into court the day before an election, desperate to avoid worsening a public health crisis. It’s quite likely that the virus will threaten in-person voting in many states and cities in November as well.

That’s why a growing non-partisan chorus has called for expanding vote-by-mail options this fall. It can be done; five states already conduct all their elections this way and every state allows some level of mail-in voting. It doesn’t favor either party – just ask Republicans in Utah and Colorado. It’s safer during a pandemic, but also secure: a study of hundreds of millions of votes in Oregon, ever since it became the first to adopt all-mail elections, found fewer than 15 fraudulent ballots cast over more than a decade.

Nothing about the Wisconsin election was normal

Republicans, however, have fought efforts to fund expanded voting options this fall. President Trump recently told Fox & Friends: “If you’d ever agreed to it, you’d never have a Republican elected in this country again.” On Wednesday, he tweeted that vote by mail creates “tremendous potential” for voter fraud and mused that “for whatever reason, [it] doesn’t work out well for Republicans”. Georgia’s state house speaker knows that reason, opposing it because it “will certainly drive up turnout” and “will be extremely devastating to Republicans and conservatives”.

But while the quiet part sometimes comes out louder than expected, most of the Republican party’s anti-vote-by-mail excuses are ludicrous. If the president’s intention is to conjure phoney visions of voter fraud, others hope to simply slow-walk reform. When Senate Democrats attempted to add election protection safeguards to the first coronavirus stimulus package, the Republican senator John Barrasso insisted they “have no place in an emergency rescue package for the American people”. Election assistance funding, sniffed his colleague Marsha Blackburn, “has nothing to do with Covid-19”.

On Tuesday, however, the connection between voting and the virus should have been clear enough for even a Republican senator to see. When Robin Vos, Wisconsin’s Republican assembly speaker, tried to deny it, he wore a mask and full personal protective gear. He looked like one of those mean government agents looking to capture ET, which only undercut his assurances that voters stacked up in the five available Milwaukee precincts had absolutely nothing to fear.

Nothing about the Wisconsin election was normal. Not voters in homemade masks, not the immunocompromised woman whose requested absentee ballot never arrived voting in full bubble wrap, not the plaintive signs that read “this is ridiculous”. But the five conservative Republican appointees to the US supreme court, concerned, ruefully and almost comically, that something might “fundamentally alter the nature of the election”, stepped in … on the side of forcing tens of thousands of Wisconsinites to brave the pandemic and vote in person.

Along a dreary 5-4 party line vote, the supreme court’s conservative majority, most appointed by presidents who lost the popular vote, overturned two lower-court rulings that had extended the vote-by-mail deadline until next week, despite evidence that tens of thousands of absentee ballots had yet to be delivered to voters who requested them, and that untold thousands more might not be postmarked in time. Ruling comfortably from their own living rooms, the five conservatives required these voters to leave their homes during a shelter-in-place order and placed them in the path of a virus. (On Wednesday, the day after the election, reports came of absentee ballots piled in post offices, undelivered.)

That the supreme court intervened not on the side of voters and fair elections, but in order to protect particular Republican partisan interests, should be saddening, yet unsurprising. Chief Justice John Roberts arrived in Washington almost 30 years ago as a young justice department appointee with a particular interest: eroding the protections of the Voting Rights Act (VRA). Under his leadership, this court has embraced his cramped vision with gusto.

John Roberts arrived in Washington almost 30 years ago as a young justice department appointee with a particular interest: eroding the protections of the Voting Rights Act. Photograph: Mario Tama/Getty Images

The Roberts court has made clear that it should not be looked to as any guarantor of the foundational right to vote. Not in an emergency. Not at all. In 2013’s Shelby County v Holder, a 5-4 court defanged the enforcement provisions of section V of the VRA and laid the groundwork for a decade of voter ID requirements, precinct closures and voter roll purges from states with documented histories of racist voting inequities.

The legislatures behind those efforts, a 5-4 court decreed in 2018’s Abbott v Texas, must be awarded the “presumption of good faith” – even for naked racial gerrymandering schemes. Those voter roll purges were upheld in 2018’s Husted v A Philip Randolph Institute, where the court, again 5-4, created a non-existent loophole that justified canceling registrations if a voter had not casted a ballot in two consecutive elections. Then last year, Roberts authored a, yes, 5-4 decision – Common Cause v Rucho – which slammed the federal courthouses closed to partisan gerrymandering claims at precisely the time a growing number of decisions, by judges appointed by presidents of both parties, saw both an urgent role for the courts and a clear standard for when politicized mapmaking crossed a constitutional boundary.

Elected Republican officials have proven that they are willing to see Americans die rather than hold fair elections

Gerrymandering and voter purges were at the heart of the GOP urgency to hold this election, this week, with this diminished turnout. A critical state supreme court seat was on the ballot. The winner could sway an upcoming appeal over whether Wisconsin can purge about 240,000 voters from its rolls ahead of November – keep in mind, Trump only won this state by 22,000 votes in 2016 – and could also determine whether Republicans, once again, have a free hand to gerrymander the state’s legislative and congressional maps in 2021. The maps the party carefully engineered in 2011, behind closed doors at a Madison law firm, delivered a 63-36 Republican edge among state assembly districts in 2018, even though Democrats won nearly 54% of the statewide vote, and a statewide edge of about 200,000 votes.

Non-partisan electoral reformers, Democratic congressional leadership, and even some apostate Republicans like Bill Kristol and the former Republican National Committee chairman Michael Steele have been battling to ensure that November’s election doesn’t look like the one this week in Wisconsin. After all, even if Congress does nothing to create a national vote-by-mail standard, there’s still likely to be record demand for absentee ballots this fall. And just as the underfunded election administrators and US Postal Service were overwhelmed by an unprecedented 1.2m requests in Wisconsin, it’s easy to imagine a creaky system collapsing under similar strains in November.

The Republican strategy is clear: drag their feet so it’s difficult to properly fund vote-by-mail. Mislead the public with fictional claims of voter fraud that get amplified on Fox News and by Russian bots on Twitter. Finally, count on John Roberts and the court’s partisan 5-4 majority to backstop any efforts to make free, fair and safe voting more difficult.

If this plays out according to the Republican plan, it will plunge this nation from an unprecedented public health crisis into a dark constitutional emergency that threatens the legitimacy of the White House, the courts and American democracy itself. That’s a frightening sentence to write. But it’s long past time we call this what it is: elected Republican officials, and the conservatives who they have handed lifelong tenure on the federal bench, have now proven that they are willing to see Americans die rather than hold fair elections that might oust them from power. They have used a pandemic to suppress votes.

The warning sirens are real. The dress rehearsal is over. There are barely 200 days until election day.