The queen reached a landmark birthday during the week when she turned 90.

Here, we have our own equivalent of a very long, uninterrupted reign. It's in Sinn Féin, where Gerry Adams has been leader for three decades now - and counting.

Such longevity is almost unprecedented in the contest of European politics. His putative successors, Mary Lou McDonald and Pearse Doherty, though still relatively young, will be seasoned veterans when the issue becomes live.

And one thing is certain - Adams is not going to step down this weekend. Relatively soon, however, we are told. When is that?

Certainly before the next general election in the South, but it would be churlish to predict otherwise.

Sinn Féin is in a strange place at the moment and that has been reflected by the mood at its ardfheis at the National Convention Centre in Dublin.

"The batteries seem to be flat," was how our Northern Editor Gerry Moriarty described it earlier. That's the most accurate summation of the weekend.

For one, it's unusual for such a conference to be held soon soon after a general election. Sure, the Northern Assembly elections will be held on May 5th. But when the convention is being held in Dublin, it does not have the same impact. If it had been held in January, it would have had much more impact.

Perhaps another reason for the sense of calm is the inertia in Irish politics over the past two months.

Tedious negotiations

With the two big parties and Independents embroiled in lengthy, tedious negotiations over the shape of a government, the political institutions are in a state of suspension.

It’s as deflating as togging out and taking to the field, only to realise that the other side isn’t showing up today.

Regarding the general election itself, sure, it was a success for the party.

Sinn Féin added an extra nine seats to take its total to 23. Compare this to the four seats it had in 2007.

Factor in the real possibility of the party taking seven seats in the Seanad. All the signs should be positive. Yet, it hasn’t quite worked out that way.

The party's expectations were too high, and amid the gains were a couple of big setbacks, no more than the loss of Pádraig Mac Lochlainn's seat in Donegal.

One lesson the party should take from the exercise is not to rely too much on opinion polls taken months before the election. They tend to overstate its support.

A much better indicator is the latest local election result - in 2014, it proved unerringly accurate as an indicator of support levels for the generals.

The first Sinn Féin ardfheis I covered was in Killinarden in West Tallaght in the mid-1990s.

The party has moved a long way from there to the ritzy surroundings of the National Convention Centre.

While many of its delegates still decry the “establishment” parties, the party is already an establishment party in the North - and is on an inexorable path to becoming one in the South.

That’s not saying it will become a Tweedle-something party. Sinn Féin will never disown its past, although as the years pass that legacy will become less relevant because it will be less proximate.

Still, there will always be a “warts and all” quality to the party that will be anathema to some people. At some stage the party will have to compromise with a conventional party (and even as a minority party). That will mean fudge.

It’s no surprise that the ardfheis majored on 1916, given that it coincides with the calendar anniversary.

The argument its detractors use - that the party was not founded 100 years ago - is slightly vacuous - everybody understands the party’s lineage and tradition, irrespective of a formal arrangement.

There is no doubt that Sinn Féin did not “own” the commemorations, as some predicted several years ago.

The reason for this is the major parties all became decidedly green-tinged (including Fine Gael), and the State’s commemoration of the Rising was undoubtedly more than a slightly counter-revisionist affair.

Sinn Féin is probably stronger than others on strategy. Its national chairman Declan Kearney reminded Raidió na Gaeltachta listeners this morning that it's involved in a "marathon", not a sprint.

The party does plan long-term, but even the best plans can become unstuck by the messy nature of politics: its “events”; the quality of candidates; policies that are too clever by half; or stuff that just does not resonate with voters.

Sinn Féin has sometimes failed to get the balance right.

In a complicated political landscape, the party may find itself out-flanked by more radical left-wing parties.

In a more fragmented Dáil, it needs to be conscious that populist out-and-out opposition might seem too opportunistic.

Sinn Féin needs to be aware of its vulnerabilities - inconsistencies of approach in the North and South, “legacy issues” that keep recurring, and the party being perceived as lacking credibility on some issues.

The main one is the economy - where it has a capable spokesman on finance, but a leader who has floundered on the specifics at critical moments.

The two stand-out performers earlier during Saturday's proceedings were Mary Lou McDonald, who gave a confident and assertive warning to Fianna Fáil on water charges, and Pearse Doherty, who followed up with a considered speech on compassionate economics with a clever reworking of Bill Clinton's famous phrase: "It's society, stupid."

Adams’s speech tonight has been much anticipated. It will be undoubtedly heavily geared towards 1916, the Northern elections - the party’s core issues.

It would be a surprise if he does not attack the two big parties.

I suspect it will be silent on his own future. He will step down some day, but not yet.