The failure of the Oireachtas to implement the Seventh Amendment has been successfully challenged

We'll have to wait for publication of the judgment to see the Supreme Court's reasons for the ruling it has made. That should happen fairly quickly.

IIRC in the High Court Heneghan argued the Art 40.1 point that FishOnABike mentions. He also argued that, once Art 18.4 was amended to allow legislation to vary the university franchise, Art 18.4.1 (the bit that says three senators for NUI, three for University of Dublin) became a sort of transitional provision, to operate until it was appropriate to make a new arrangement under the new 18.4.2.

So far as I recall, the amendment to Art 18.4 was proposed and adopted in 1979 because there were plans to dissolve the NUI and create separate universities in Dublin, Cork, Galway and (probably) Maynooth. At some point the plan was abandoned; NUI was not dissolved and the politicians saw no need to use the power conferred by Art 18.4.2.

Instead we've had the establishment of new universities (Limerick, Dublin City), a growth in Irish institutions providing degrees validated by foreign universities, and the award of degrees validated not by universities but by bodies like the old NCEA and HETAC. So we now have lots of citizens who have obtained degrees in Irish institutions but whose degrees are not awarded by NUI or Dublin. And this is exactly the situation that was foreseen in 1979, albeit that we have arrived there by a different route.

I'm guessing here, but I suspect the argument will be along the lines that the people amended the Constitution in anticipation of the dissolution of NUI so that Irish graduates could continue to participate in Seanad elections even when there was no NUI. Had the State in fact dissolved NUI the intention of the people was clearly that they would legislate under art 18.4.2 to include graduates of the successor universities. Instead of dissolving NUI, they created new universities and degree-awarding bodies, but this technical change of policy shouldn't be allowed to frustrate the intention behind the enactment of Art 18.4.2. The Oireachtas has a responsibility to exercise its powers under Art 18.4.2 to regulate the university franchise in a way that takes account of the higher education environment in Ireland and that is compatible with the Art 40.1 guarantee of equality before the law.

Partly it's an accident of history. University representation survived because it meant that unionist voices would be represented in the Oireachtas of the Irish Free State.

That's not so much a consideration now. The main defence of the system nowadays is the pragmatic one that it produces pretty good outcomes - the university constituencies punch well above their weight in terms of returning competent, articulate, independent voices who make a positive contribution to the Parliamentary process and represent a variety of perspectives that probably wouldn't otherwise be heard in the Oireachtas. The bulk of senators are elected by county councillors; they are party hacks who you've mostly never heard of unless you heard of them as TDs who lost their seats. The Seanad would not be improved if it had six more of those in place of the university senators.

Senators are not supposed to represent anybody, much less represent the people who elected them. You are represented by your TDs but, even if you happen to have a vote in the Seanad elections, your Senator does not represent you.

(Thus, as a Seanad voter, you are not supposed to elect the candidate who will favour you/your university, but the candidate who you judge will make the most beneficial contribution to the deliberative process.)

I don't think your point is valid. Non-degree holders don't have to defer, listen and know their place; they elect Dail Eireann, which can and does override the Seanad. University graduates only get to select a small minority of the members of one House of the Oireachtas which is unable to impose its will on the other House.

Nor is it correct to say that "people still vote for closest ideology" in the university seats, since the university sets tend to return a high proportion of independent senators. I suspect most people who have votes in the Seanad as university graduates cast them for candidates who are not aligned with the candidates the same people vote for in Dail Elections; the results would certainly suggest that they do. And the received wisdom is that a party alignment, even with a major party, is a handicap in university seats, not an asset.

I agree that its hard to justify the university franchise for Seanad seats on democratic grounds, but most electoral systems are a compromise between what would be maximally democratic and what will produce a competent and functioning legislature. The defence offered for the university seats is that they improve the quality of the legislature.

In general, "may" is permissive, and "must" and "shall" are mandatory. But all legislation, and the Constitution in particular, is to be read holistically, to give effect to the comprehensive intention of the legislator (which, the case of the Constitution, means the intention of the people). So "may" can sometime mean, well, something a bit more than "may".

For example, there's the case of Doyle v Hearne where the Supreme Court looked at a provision in the Courts of Justice Act which said that a circuit judge may refer a question of law that is relevant to case before him to a higher court and may postpone giving judgment in the case before him until the higher court has given a ruling on the question of law. The Supreme Court held that the second "may" was mandatory; it would be absurd to interpret the Act so as to allow the circuit judge to put a question of law to a higher court but then go ahead and determine the case before him without waiting for an answer.

This case, obviously, isn't on all fours with Doyle v Hearne, but it makes the point that what "may" means depends on the wider context; the purpose of the legislation; the problem it is trying to solve; the way in which it is trying to solve it. The goal of interpreting legislation is to give effect to the intention of the legislator, so the question really comes down to: what did the people intend when they made this amendment to the Constitution?

This isn't a ruling that every instance of the word "may" in the Constitution indicates an imperative; just that this one, read in its context, does.

That is also what the state contended in the court proceedings. But it's not a contention that found favour with the court.

The judgements have now been published. They point out that the language of the amendments is deeply, deeply confusing. Almost any meaning you think might have been intended would have been more clearly expressed using different language.