A calling card for some of the most ignorant people in British politics is an obsession with the idea of abstentionist Sinn Féin members of parliament storming the doors of the House of Commons, pledging allegiance to the Queen, and tipping the balance of a close vote at the last minute. The history of the party’s Westminster stance matters little to these political daydreamers. For them, the Irish republican party exists purely to embroider their idle fantasies — bolstering roll call numbers to win short-term political battles rather than maintaining a stance backed by the voters who return them each election.

Sinn Féin voters are aware when they cast their ballots that the candidates won’t take their seats or attend the state opening of parliament with the Queen. The party does still hold offices in Westminster, and lobbies for its constituents’ interests, but its members eschew the chamber, refuse to pledge allegiance to the monarch, and do not take a salary. Their supporters haven’t been duped: if they suddenly took their seats in Westminster it would be a far greater upset to their voters than many English political journalists can grasp.

But insofar as it is possible to have a good Brexit, Sinn Féin are having a good Brexit. Although their ideological opponents, the Democratic Unionist Party (DUP), are propping up Theresa May’s minority government, the DUP have shown they wield little power despite the amount of media fuss they kick up.

The DUP refused to vote for May’s withdrawal agreement on the grounds that it includes a “backstop” on the Irish border, which, they argue, would lead to Northern Ireland being treated differently than the rest of the United Kingdom, and more akin to the Republic of Ireland. Withholding their ten votes made little difference: May lost horrendously, by 230 votes, the biggest government defeat in British electoral history. But the confidence vote the following day was won only with the help of the DUP: had the party voted the other way, May would have lost it.

Speaking immediately after the no-confidence vote result was announced, Nigel Dodds, leader of the DUP group in Westminster, underlined “the importance of the supply and confidence deal” by which the DUP prop up May’s shaky government, and thanked the prime minister for the £1 billion “investment” bribe she had handed them as a condition of the party coming on board.

But the DUP remain stuck: Dublin and Brussels will not budge on the border issue, and the DUP claim they cannot countenance the backstop in any shape or form. Sinn Féin MP Micky Brady told me that “the last forty-eight hours have just served to deepen the chaos and dysfunctionality inherent in British politics around Brexit,” and that the party’s focus was on preventing a hard border. Sinn Féin backed May’s withdrawal deal with its backstop arrangements to prevent said border changes, while the DUP opposed the deal vociferously.

But if a no-deal Brexit comes to pass and the UK crashes out of the European Union, the DUP still won’t necessarily have won: most people in Northern Ireland voted to remain in the EU, and the appetite for a referendum on Irish reunification increases in tandem with the prospect of the restoration of a land border in the UK requiring checks and patrols, in a return to an earlier era of conflict. Even May herself has warned that prospect is a highly likely one.

Even when I’ve spoken to Unionist voters, not one has told me they back the DUP’s approach: the majority of them are small business owners and a seamless border is essential to their livelihood. They’re happy for Northern Ireland to remain part of the United Kingdom, but would balefully prefer a united Ireland to the DUP’s hard Brexit causing mass upheaval in their daily lives.

Either the border remains unchanged and the backstop is implemented against the DUP’s will, in which case Sinn Féin can argue they’ve won and put Northern Irish voters first; or the UK crashes out and the DUP risks the breakup of the union through their own pigheaded refusal to be flexible and diverge from their own strict ideology. In which case, again, Sinn Féin will happily campaign for a reunified Ireland.

The DUP are in power, but utterly powerless: swaggering around Westminster making a lot of noise, but with no one truly listening to them. They remain frozen, used minimally by the Conservatives to keep Corbyn out of power. But their greedy power grab may do them in entirely, while boosting their nationalist political enemies.

The Liberal Democrats were chewed up and spat out by the Conservatives. The DUP, having apparently learned nothing, are now risking the entire Union, handing Sinn Féin endless political opportunities in the process.