The decline of the Ulster Unionist Party is signalled by its loss - for the first time - of its voice at Westminster.
Sir Reg Empey's failure to recover South Antrim last Thursday confirmed the truth that the rank-and-file of his party are like most other political activists in Northern Ireland: they have no strong desire to play a part in the political life of the UK at national level.
Many have a regard for their British citizenship; but its main element would now seem to consist of the money - the British benefits.
In the early days of the party, though, fighting the Liberals' bid to hurry on Irish Home Rule in the 1880s, it was different.
The pre-partitioned Ulster sent 18 Conservative MPs to Westminster. The climax came during the First World War when Edward Carson served first as Attorney-General under Asquith in the Liberal-Conservative coalition, later as First Lord of the Admiralty under Lloyd George and was mentioned as a future premier.
Stormont's first and future Prime Minister, James Craig, served as a junior minister in the wartime coalition and - in 1920 - also went to the Admiralty.
Since then, apart from Robin Chichester-Clark's junior ministry under Ted Heath in 1972, it has been a blank sheet.
David Cameron promised Sir Reg Empey office in a Conservative Government. It was part of the UCUNF deal.
It is significant that the promise seemed to cut little ice with the electorate.
The DUP was preferred, presumably because its gaze has always been relentlessly inward-looking. There is irony in the prospect that it is to the votes of DUP MPs that Cameron may eventually have to look in the new Commons arithmetic.
Cameron's problem is that political memories are notoriously long in Northern Ireland. The wounds of 1972, losing Stormont, and 1985, the hated Agreement, were each inflicted by Tory governments - and they are not forgotten.
Tory Secretaries of State, like Patrick Mayhew, boasting of their Irish connections and their appetite for the job, proved a grave disappointment to the UUP.
But it was the DUP which articulated this most clearly, for their stuff was fundamentalist: street politics with the gloves off . Times have moved on, but the gut feeling remains.
It showed last week in South Antrim - and in North Down, where Lady Hermon ran on an openly anti-Tory ticket, was not opposed by the DUP and trounced her UCUNF challenger.
There is also the class issue. Paisley, the founder, is the archetypal populist politician - muted now, but once loud, belligerent, asking no quarter and giving none.
The then Prime Minister, Terence O'Neill, rather disdained him. O'Neill was never a Big House man himself, though he made the mistake of having been born in London, of going to Eton and of returning to Hampshire when Paisley forced his resignation in 1969.
But the UUP, at one time, was the party of the Brookes of Colebrooke, the Chichester-Clarks of Castledawson, the Clarks of Upperlands, the Dixons, the Cunninghams and the rest.
The Orangemen among them even had their own lodge, with wine and canapes at the field. But when the social pendulum swung, as it has, they found it was no contest.
The DUP makes it clear that their approach to Tory or Labour will be quite detached: their support will go to the highest bidder. Sounds cool; but we may have been here before.
Cameron, once in Number 10, could promise much - in due time - and then call a second election come October which could give him his majority.
One Parliament cannot bind another. The slate would be wiped clean.
But at this moment interesting times lie ahead. Head teachers are due to boycott the Sats tests this week. Unite and the RMT have sworn to oppose Government cuts. Civil servants are poised to call strike ballots if their pay is frozen. NHS cuts in Northern Ireland are already on paper. An emergency budget is promised.
What price DUP votes for all this?