In Northern Ireland's centenary year, some in unionism are starting to debate collapsing Stormont in protest at the protocol.
It's the height of irony that the British politician bringing them to the brink is not Jeremy Corbyn - whom they spent the life of an entire parliament denouncing as a republican sympathiser - but the man many of them once praised to high heaven.
Not so long ago, it looked like Boris and Arlene would rule the realm in harmony for years to come as they stood regally on that balcony in Parliament Buildings. There's plenty in her party who would now throw him off it given half a chance.
The DUP leader isn't the first woman he's betrayed, and she likely won't be the last. Ian Paisley famously called Margaret Thatcher "Jezebel" over the Anglo-Irish Agreement. One wonders what damning diatribe he would unleash on Boris Johnson's head were he still around.
The prime minister threw the DUP under a bus, and then reversed over it. Why oh why would any unionist invest an ounce of hope in him now faithfully fighting their corner? There are no votes inside or outside Parliament for him in that.
In typically forensic fashion, Peter Robinson has laid bare the political reality facing unionism.
"One lesson learned after decades of dealing with governments is that they don't yield unless life has become uncomfortable," he wrote in Friday's News Letter. "Statements and speeches will not turn them nor, frankly, will petitions and debates."
That was hardly a vote of confidence in his party's five-point plan to address the Irish Sea border. Robinson was right to sweep away the window-dressing, and get down to brass tacks. The DUP's blueprint is first and foremost an attempt to pacify its own grassroots. It's about creating the illusion of action.
Ultimately, unionists must choose whether to 'suck it up' - the protocol as it is, or slightly amended - or to threaten to bring down Stormont. Loyalists say that, without the pandemic, there would be feet on the streets. That's undoubtedly true, but it would be nowhere near the 100,000 plus that came out against the Anglo-Irish Agreement.
Unionist anger now is nowhere near the level that makes for monster rallies. Besides, that massive demonstration outside Belfast City Hall in 1985 changed not one line of the document that Margaret Thatcher and Garret FitzGerald had signed. The flags' protests were on a much more modest scale, and they too fizzled out in failure. Neither did the Drumcree Orangemen win.
The protocol is just six weeks old and, if London and Brussels can resolve some of the trade problems it has created, then much of the heat will be taken out of the situation. That will be the tweaking and "tinkering" to which Peter Robinson referred. It won't satisfy those whose opposition is purely ideological, but it will mollify unionists whose concerns are primarily about products, not principle.
If Brussels doesn't budge enough, then the DUP has a big call. Taking action that would effectively bring down Stormont is high-risk stuff. Would Arlene Foster really chance an early Assembly election?
The Duppers would surely lose a significant chunk of moderate voters to Alliance. The worst of all worlds for Foster would be if such drastic action wasn't enough to stop the haemorrhaging of hardline support to the TUV.
If Michelle O'Neill ended up First Minister - and that may well happen anyway in May 2022 - then it's immediately over for Arlene as leader.
Collapsing the institutions perfectly fits Jim Allister's political outlook. Far from inconveniencing Sinn Fein, it might even suit the party electorally.
The DUP needs devolution to work far more than a republican rival which ultimately has its eyes fixed on a border poll. That's why - whatever course of action Foster takes - she will be mindful of the dangers of choosing the nuclear option and crashing Stormont.