The cruel and cowardly murder of Constable Ronan Kerr should not be read as a sign of the frailty of the political institutions in Northern Ireland, but a challenge provoked by their relative success.
It also constitutes a challenge to elected politicians to carry the process through to stability and the efficient delivery of services.
More specifically, the attack on Ronan Kerr is evidence of a viciously sectarian strategy targeting Catholic members of PSNI, aimed at encouraging them to leave the service, and deterring other young Catholics from joining.
This would roll back the Patten reforms, transforming the service into a Protestant force, which could be vilified and attacked as an instrument of oppression.
It is not without significance, however, that the past 10 days also marks a comparative triumph for politics in the north and for the institutions set up under the Good Friday Agreement.
The Assembly and Executive have crept to the quiet achievement of fulfilling the statutory four-year term without suspension or walkout and effectively demonstrated that society had moved from violence to politics.
At the most basic level, their achievement has been to survive. An optimistic end-of-term report would record that they had laid the foundations for civility and stability, building the relationships and the trust essential to further progress.
The same benign assessment would recognise the transfer of responsibility for policing and the administration of justice to the Assembly as an important milestone.
The ability to manage a function that had been deeply divisive is a major statement of the wish and the ability of the parties to provide effective government. It also requires a response from the public in the practical support that will assist the police in bringing the killers to justice.
A more realistic report-card would be more disappointing - the Assembly a talking-shop, the Executive an arena for competing egos and party rivalries. Most of all, they lack the semblance of joined-up government without collective responsibility and ministers acting as competing barons in their own domain.
Their main failure has been in capturing the public imagination. People notice the absence of war, but not the presence of government (except when it goes badly wrong, as in the water crisis early in the year).
The figure to look out for in the coming election is the turnout. While it is a triumph for the process that the issues in the election are economic and social policies, rather than competing views of constitutional status, the potentially greatest challenge to the parties is voter apathy.
Martin McGuinness has displayed remarkable maturity in office and has grown in stature, scarcely putting a foot wrong.
Peter Robinson has emerged from a difficult period as a more rounded person with a renewed commitment to make a go of things with McGuinness. The main example of a minister determined to go his own way is Ulster Unionist Michael McGimpsey at Health.
He appears to have the odd notion that his department should uniquely be protected from the cuts occasioned by the state of UK public finances.
He has also delivered an electoral Exocet to his party's prospects in the North West, in professing not to be able to find, in a budget of £4bn, the money required to train staff for a radiotherapy centre in Derry. Even at this stage in the campaign, it is safe to predict that the outcome will see a consolidation of both DUP and Sinn Fein as the largest parties on both sides.
They will dominate the new Executive.
What is necessary for them and the other parties is to agree a programme of government and to submit to some code of collective accountability and common purpose which would make the Executive more like a Cabinet.
Failure to consolidate the political institutions - even in times of economic challenge - can only provide space for dissidents to exploit. There is nothing as corrosive as public disillusion with politics and politicians.
That is the challenge for politicians of all parties: to get together and provide effective services; to prove that politics does work.
It cannot be right that brave young policemen should carry all the risk.