Two of Seamus Mallon's defining characteristics as a politician have been honesty and tenacity. His statement yesterday used tough language to put across a blunt message: after the unionists had scorned the massive vote of the people backing the Belfast Agreement, it was his responsibility as a democratic politician to resign from any privileged position he held under it.
Mr Mallon, the deep-green nationalist from south Armagh, is also a straight-talking Ulsterman. Mr John Robb, the radical Protestant who served with him in the Seanad, recalls a north Antrim neighbour and strong unionist admiring Mr Mallon for his directness, for "speaking his mind - you know you're getting the real thing with him".
Seamus Mallon, now 62, grew up with unionists in the largely Protestant town of Markethill, and knows how they tick. Among nationalist politicians, he is probably the one who best understands their dilemma in having to learn to adapt to a modern world where they are no longer a kind of master race, but must face the realities of equality, power-sharing and an Irish dimension.
In political terms, this seemed to make him the perfect Deputy First Minister to David Trimble, although the two men's similarly trenchant and often aggressive exteriors made for a prickly personal relationship.
As long ago as the mid-1970s Mr Mallon was criticising the IRA for not understanding that the more unionism was attacked, the more its "different shapes and hues" consolidated. On the other hand, "the more you treat with them, the more they disintegrate".
Despite - or perhaps because of - such insights, Seamus Mallon's reputation with unionists until recent years was as a tough, uncompromising nationalist.
His first political involvement was chairing his local civil rights committee in the 1960s, and he joined the SDLP in 1972. He made his name when he was first elected to the 1973 Northern assembly as an outspoken critic of the security forces.
He is an unflappable and tough-talking debater, with an ear for the telling one-liner. Everyone remembers his taunt to Sinn Fein in the run-up to the Belfast Agreement that when all its "verbiage" was stripped away what was being talked about was "Sunningdale for slow learners".
For many years in the late 1970s and early 1980s he was effectively out of a job, relying on substitute teaching and the occasional US lecture tour to keep his family fed and clothed, until Charles Haughey gave him a Seanad post.
He admitted in a 1984 interview that despair was a frequent visitor, but one that passed and left hardened resolution in its wake.
His entire career has been based on the passionate belief in the primacy of politics in Northern Ireland.
As a constitutional politician, he felt he was playing a vital role in two key areas - preventing the North from tipping over into anarchy and civil war, and helping nationalists to redefine their deeply-felt ideology to make it constructive rather than unrealistic and aspirational.
When he was elected Deputy First Minister last June, it was hard to find a politician of any stripe with a bad word to say about him. John Taylor called him someone who would "work for the good of Northern Ireland." Sinn Fein's Rita O'Hare said he was a "formidable opponent, but always honest and honourable." Ken Maginnis said he would "trust Seamus Mallon with my life".
Then the man from Markethill was being hailed as one of the two key trust-builders in the new Northern Ireland. A month later he joined his partner in that awesome task, David Trimble, in facing down the extreme loyalist elements trying to use Drumcree to destroy the Belfast Agreement. A year on, what he sees as a fundamental breach of trust by the Ulster Unionist leader has led to his starring role in the North's latest setback.
