David Trimble's position as leader of the Ulster Unionists looks increasingly precarious as a formal review of the Good Friday Agreement opens on Tuesday.
Sinn Fein and the Rev Ian Paisley's Democratic Unionist Party (DUP) have emerged as the dominant representatives of Catholics and Protestants, and the Belfast Assembly remains suspended since there is no immediate prospect of a deal between them.
Mr Trimble's Ulster Unionist Party (UUP) and the moderate Catholic SDLP have been relegated to second place, after finishing well behind their rivals in last year's assembly elections.
The repercussions of the election result are still coursing through the Ulster Unionists, with walkouts in a number of branches and demoralisation among activists.
The prospects are for the virtual eclipse of Mr Trimble, who has been at the centre of political negotiations for more than five years. Names of potential successors are being discussed in Unionist circles.
Garfield Gilpin, a former vice-chairman of Mr Trimble's own Upper Bann association, warned: "David Trimble has got away from basic Ulster Unionist principles and no longer represents the majority of grassroots traditional unionism. The wheels are falling off the machine."
Few can see how the UUP can claw back the ground lost to its more extreme rivals. The assembly vote indicates that Sinn Fein and the DUP are on course to take almost all the province's 18 seats in the next Westminster election.
The DUP's electoral advance was followed by the defection to the party of three of Mr Trimble's members, led by Jeffrey Donaldson MP. This means Mr Paisley commands 33 assembly seats while Mr Trimble holds 24.
At a recent rally the DUP deputy leader, Peter Robinson, declared: "For unionism the politics of Northern Ireland has now changed, radically, extensively, irreversibly and favourably. Unionism is under new management."
Most participants in the peace process have come, generally with reluctance, to accept the assessment that control of unionism has passed from Mr Trimble to the DUP. Mr Trimble is now so far behind the Paisley party that any deal will have to be between the DUP and Sinn Fein.
The previous pattern of negotiations in which Mr Trimble was closeted for intensive talks with Gerry Adams of Sinn Fein is expected to change as Mr Paisley and Mr Robinson have emerged as unionism's principal voices. And having been at the top for so long, Mr Trimble may see little point in heading a party which in all probability will be in second place within unionism.
The nationalist SDLP, meanwhile, suffered a crushing defeat at the hands of Sinn Fein, which now has 24 assembly seats to the SDLP's 18.
Sinn Fein hopes to increase its vote still further in June's European elections, both in Northern Ireland and in the Irish Republic.Although efforts will be made during the review to find common ground between republicans and the DUP, few believe that real progress is possible before the onset of the European election campaign closes down the negotiating window.
The general perception is that Mr Robinson is more inclined to be pragmatic than his party leader, but most observers also believe that it will take time for a more flexible line to come through.
During the review, the DUP is to produce proposals for a new style of government, but these are thought unlikely to be attractive to nationalists.
The British and Irish governments, meanwhile, worry that in the short term Sinn Fein will decline to make any meaningful concessions to the DUP.
One theory is that both the republicans and the Paisleyites are unlikely to get down to business until after the next Westminster election, when the two expect to be undisputed masters of the political scene.
The SDLP is widely seen as a lost cause. There is more hope for the survival of the UUP, though much of this is due to the unlikely scenario of the DUP making serious tactical errors to allow a UUP revival.Reuse content