Democracy is fragile. It can never be taken for granted. Its quality can wax, but it can wane too.
As so many examples from around the world show, democratisation is not a one-way street towards more and ever-better democracy. The process can go into reverse. Nor does having democratic institutions guarantee democratic practices, habits and values, as - again - many examples in other countries prove.
Sinn Fein is potentially months away from being in power in both jurisdictions on this island. A central question for the Republic's politics is the degree to which that party has evolved away from the anti-democratic culture and values it had (and had to have) when it was part of a military force engaged in a campaign of violence over decades.
Last week's allegations by Mairia Cahill against Gerry Adams, Sinn Fein and the mainstream republican movement highlights the need to subject that party, and its wider organisation, to great scrutiny.
The allegations of protracted sexual abuse of a minor by an IRA member; of kangaroo courts involving high-ranking republicans acting as judges; and of implicit, if not explicit, threats of violence are all extremely serious. They are all the more so given Mairia Cahill's further allegations that there are other victims "north and south" numbering in "double figures".
Are republican figures still involved in sexual abuse? Is abuse systematic? How many other victims are there? Have they been silenced? If so, how? What, if anything, has been done by the organisation to end sexual predation by its members? Are kangaroo court methods still being used by the republican movement in dealing with sex abuse allegations? Is a parallel "justice" system being operated in relation to other types of wrong-doing by members? Has the republican movement subverted the formal justice system in the North and does this explain why the PSNI and the North's DPP were so slow and seemingly half-hearted in dealing with Mairia Cahill's case? To what extent has the Balkanisation of the North that has taken place under the 1998 political settlement allowed Sinn Fein and the DUP to run two parallel states as fiefdoms? Have citizens of this state been hauled before the sort of kangaroo courts that Mairia Cahill claims she was put before?
If there were no other cases that raise questions about the republican movement's adoption and internalisation of democratic values, there would be less to be concerned about. But there are many other cases.
In 2004, a decade after the first IRA ceasefire, Robert McCartney was pulled from a crowded Belfast pub and beaten to death. The senior IRA figures involved threatened the dozens of people who witnessed it. Nobody has ever been convicted of the murder.
If legacy issues from past crimes were the only matter of concern, and there were no suspicions that the republican movement was still engaging in criminality, it would be one thing. But fresh issues continue to arise.
After Gerry Adams was arrested in April this year in connection with the murder of Jean McConnville, focus quickly turned to the source of material upon which the PSNI arrested him, which came from interviews republicans had given to researchers for an academic study. Communications between the wife of one the researchers and the US embassy in Dublin were allegedly leaked to the press.
This is a murky case, and there are a number of other actors who could have engaged in such surveillance, but if it happened and if republicans were behind it, it raises very serious questions about the extent of IRA activity and whether that organisation maintains a highly-sophisticated spying capacity which could be used against its political opponents and others it wants to damage.
As the journalist Ed Moloney wrote in his letter to the Taoiseach about the case "tapping the phones of Irish citizens in any circumstances is unpleasant and offensive even when it is carried out within the law by legitimate agencies. But when it is done by illegal organisations and involves intercepting communications by an important ally it is, I am sure you will agree, a direct challenge to the authority of the state".
All of this leads to even broader questions. Why does the IRA still exist? More than 15 years after the Good Friday Agreement, why has it not disbanded? Is it an old boys' club with dwindling membership or is it still recruiting? Does it continue to claim to be the only legitimate armed force on this island? How closely linked is the IRA to Sinn Fein? Have the two branches grown apart or are they - as they were during the Troubles - one and the same for all intents and purposes? Does the civilian wing control the military wing, or is it vice versa?
The last question is important in a number of respects. Civilian control of the military is a cornerstone of all democracies because soldiers' values in wartime are not the values of democracy.
Being at war requires, perforce, the nurturing of military values and practices - obedience, secrecy, suspicion and summary justice. These are the exact opposite of the values and practices that make for high-quality democracy - the questioning of authority, transparency, trust and the rule of law. The North's long war lasted from the late 1960s into this century. Two generations went from youth to middle age knowing nothing else. That deeply embedded a martial culture in the republican movement. It is far from clear that that has changed a great deal.
Killian Forde, a former Sinn Fein councillor, quit the party in 2010 and spoke of it being "cultish" and "anti-democratic" in an interview. Separately, in a note he circulated internally before leaving and published subsequently on sinnfeinkeepleft.blogspot.ie he wrote "Sinn Fein and republicans value loyalty and obedience, probably above any other virtue... There is little tolerance for dissenting opinions and nowhere for people to take those opinions. Criticism and accountability of the leadership has been discouraged for so long that, simply put, there is a culture of fear…".
It must be the sincere wish of all democrats on this island that a party with as much support on both sides of the border as Sinn Fein evolves and becomes a thoroughly constitutional party and that all its war-era baggage is consigned to history.
But it would be wrong to assume that will happen by some unspecified automatic process.
It's a shameful indictment of our society when a sexual abuse victim has to retell her experiences over and over again in the glare of the media in order to rebut the weight of a political party closing ranks to defend itself and a leader who, at the best of times, has trouble remembering detail.