DUP has a strong hand over Article 50 - which is why it must play it wisely
This is the moment for the party's eight MPs to be useful to Theresa May, but she won't barter for their votes if the cost is the likely end of the Assembly, says Alex Kane
While the Supreme Court's decision - forcing Theresa May to win a parliamentary majority before she can trigger Article 50 - didn't come as a huge surprise to her, it still muddies the waters.
She has a working majority of just 16, but she also has a group of potential backbench rebels who may decide to put their consciences before party policy.
They can argue that she doesn't have a mandate for her "Brexit means Brexit" strategy, and some of them can further argue that they campaigned for Remain, and that's how their constituency voted.
If just nine of them indicate a willingness to defy her then she has a huge problem in terms of pushing an Act through Westminster before the end of March.
Step forward the DUP's eight MPs to offer her support. According to Sammy Wilson: "The battle now commences at Westminster and, as far as the DUP is concerned, we will be using our votes and voice to ensure a rapid commencement on the negotiations to leave the EU completely, as the Prime Minister promised, while at the same time ensuring that, in the absence of any Assembly voice, the issues most concerning to Northern Ireland are articulated by our MPs."
Nigel Dodds added: "We expect the Government to bring forward legislation which will deliver the Brexit the DUP campaigned for and which will be in the national interest. It is vital to get this work in the Parliament right and we will ensure that it does.
"The DUP campaigned for Brexit and we believe we are stronger outside the shackles of the European Union. We voted as a whole to leave the EU and that vote must be continually respected."
No nuance, or "constructive ambiguity", in those statements. The DUP clearly favours a "hard" Brexit. And its hand has been strengthened by the fact that the Supreme Court also confirmed that the Northern Ireland Assembly (along with the Welsh Assembly and Scottish Parliament) will have no right to veto or impede May in Parliament.
So, the DUP, which didn't deliver a Leave majority in Northern Ireland last June and wouldn't be able to deliver a Leave majority in the Assembly, may still be able to prop up - even save - the Prime Minister in the event of a rebellion by a handful of her own MPs.
No small party finding itself in that position would fail to extract the political equivalent of Danegeld from the Prime Minister, particularly at a moment when it could be facing its own problems in rebooting the Assembly after what is likely to be a very divisive election, followed by a potentially fractious talks process.
In other words, in exchange for "helping" the Prime Minister, the DUP will expect the Prime Minister to "help" it in six weeks' time.
But how far can May go? She already has enough on her plate in trying to get an Act on the statute book before the end of March without risking the collapse of a talks process and facing the prospect of either a very lengthy period of suspension, or even the return of formal direct rule. She will know that she needs to tread very carefully. DUP votes could be important for her; but she won't barter for them if the price is the possible end of the Assembly and the political process as we know it.
And nor can she ignore the fact that a majority of Northern Ireland's MPs (two UUP, three SDLP, four Sinn Fein and Lady Hermon) and four of the five main parties in the Assembly supported the Remain side during the referendum.
Or that Northern Ireland as a whole, on a bigger turnout than for the Assembly election, voted or Remain by 56%-44%.
While the DUP seems to be quite happy to opt for the hard form of Brexit - with all of the ramifications that could have for UK/Republic of Ireland relationships and relationships between nationalists and unionists here - all of the political/electoral evidence points to the fact that theirs is a demonstrably minority position. Those facts and that evidence will steer her towards caution in her dealings with the DUP.
Where the DUP's influence could be crucial, though, is in ensuring that the particular difficulties which could face Northern Ireland when the UK leaves the European Union will be properly assessed and addressed over the next couple of months.
Such an approach would reflect the wishes of the majority here (including those of many, many unionists); would make it easier to reach a new post-election rapprochement with Sinn Fein, and would allow the British/Irish Governments to reach an agreement that could be underwritten by the EU.
At some point it seems likely that the DUP leader will reassume the title of First Minister. So it makes sense, surely, to ensure that the party's seeming desire for a hard Brexit doesn't become a wrecking-ball for local power-sharing.
The DUP's position today is firm: "Sinn Fein and those Opposition parties which produced the crisis to bring down the Assembly have ensured that the mechanisms set up to deal with NI-specific issues have been effectively scuppered.
"However, the DUP will hold the fort to ensure that the UK will leave the EU and at the same time take part in negotiations with the same stance on Brexit, reflecting the issues affecting us."
That, of course, is absurd. The DUP does not have a mandate to represent Northern Ireland on Brexit. Negotiating on that basis would be a folly.
Which is why I suspect it won't go too far down that path, not least because the Prime Minister will not let it.
She is aware that it doesn't speak for Northern Ireland, just as she is aware that it is in the long-term interests of London, Dublin and Belfast to ensure that nothing is done to undermine a peace/political process that took so long to construct.
This is a moment for the DUP to be useful to the Prime Minister, but its usefulness must be used as a way of strengthening Northern Ireland's position within the Union, rather than weakening it.
The referendum demonstrated that a substantial majority of the electorate here is well disposed to the EU, so the DUP has to be careful not to pursue a policy that leaves those people questioning the value and values of the vision promoted by the DUP in June 2016.
The DUP has a strong hand to play: it must play it wisely and for the collective advantage of Northern Ireland, rather than for its own immediate electoral interests.
Brexit is already seen by Sinn Fein and some elements of the Irish political establishment as a potential vehicle for earlier-than-expected Irish unity, so the DUP needs to be very careful that it doesn't provide any fuel for that vehicle.