Gerry Adams entry into the fray turned row toxic - if McGuinness had been well he would have found a way to some kind of compromise
The DUP deserves most of the blame for exposing the abused Northern Irish electorate to an unnecessary election, but Gerry Adams has played a major part in turning a problem into a crisis.
Had Martin McGuinness - the brains of the republican movement - been well, I can't believe that he wouldn't have found a way of achieving some kind of compromise with Arlene Foster.
Civility and respect can achieve a lot, and Mr McGuinness has used both to considerable effect in helping keep three relationships with DUP leaders motoring along with only the occasional puncture.
But not only has he been too ill to do his job, he's clearly too ill to control his stand-in.
Let's not kid ourselves that Mr McGuinness is the peacenik he pretends to be.
He's a pragmatist who opted for politics only because the IRA was defeated.
But though as hard a man as Mr Adams, he's not similarly driven by vanity and ego.
If anything was calculated to make an obstinate DUP leadership become irrationally stubborn, it was the arrival on the scene of Mr Adams.
As former DUP MLA David McIlveen put it last week, the DUP leadership "seem to be confused around the difference between humility and humiliation".
Mr Adams ensured there was no chance of helping them to see the difference.
The very fact of having the leader of a political party from another state tramping in on delicate ground was bad enough.
But to have the likes of Mr Adams taking a high moral tone on the proper conduct of government and hectoring you on your duty as a constitutional politician would cause the meekest saint to shout "No surrender".
In earlier times, Dublin, London or Washington would have been expected to send emissaries to bring the two warring sides together, but the truth is, that for most purposes, everyone is far too busy to care.
In case Gerry Adams hasn't noticed, Dublin and London are utterly absorbed in the politics of Brexit, while Washingtonians are gazing nervously at their Twitter feeds to see what Donald Trump will say or do next.
Trying to be kind, I acknowledge that Gerry Adams must be in a pretty awful emotional state, which could be contributing to his dreadful handling of nearly everything these days.
Where is the glorious Republican project now?
By 2016 there was supposed to be a united Ireland.
Well, that didn't happen, but the republican leadership still thought there was still an excellent chance that Mr McGuinness could win the 2018 presidential election and Mr Adams would get into a coalition government and start turning up the heat on Northern Ireland.
That was also unlikely, not least because of the loathing most southern politicians feel for Mr Adams, but he could hope.
He must be looking at the fragile Mr McGuinness, with whom he lived through dreadful times often doing dreadful things for close on 50 years, and he must be fearing for the future.
The DUP should recognise that when he howls at them, he's howling at the moon.