Last Sunday Enda Kenny made a surprise announcement during a speech in Philadelphia, the city where the American constitution was drafted 230 years ago.
Unexpectedly, the Taoiseach gave a commitment to hold a constitutional referendum on granting voting rights in presidential elections to citizens not resident in the state. The announcement came three years and four months after the constitutional convention, which reviewed many aspects of the State's legal superstructure, strongly supported extending the franchise in presidential elections.
Kenny's announcement seven days ago, appropriately timed in the run-up to St Patrick's Day, should be welcomed. It is a meaningful gesture towards the diaspora and should benefit everyone - at home and abroad - by increasing the involvement of those resident outside the state with their home country. If there is an aspect of the proposal that is deeply problematic it is the inclusion of citizens in the other jurisdiction on this island, an issue discussed below.
A more general criticism of non-resident voting, and one that has been made over the past week, is that it violates the important principle that all citizens' rights should be matched with responsibilities, or, more specifically in this instance, that one should not have political representation without contributing via taxation. This is a more serious issue for Ireland than most other democracies as a larger share of the native-born population (17.5pc) lives abroad than any other state among the 33-nation OECD group of countries.
This issue would be crucial if last Sunday's proposal involved giving non-residents the right to vote in general elections and/or referendums as that would allow many people a say in how the country is run, but without having to live with the consequences.
It could even result in those living abroad changing the outcome of votes - in 2006 Silvio Berlusconi would have retained Italy's premiership in that year's general election had it not been for votes of expatriate Italians who, incidentally, account for just over 4pc of the population. Given Ireland's unusually large diaspora, it would be distorting to the democratic process to give non-residents the same say in Dail elections and referendums as those living in the country.
But presidential elections are different from general elections and referendums. As the presidency is largely ceremonial and the incumbent does not make policy, granting those who do not live here a say in who is president does not violate the principle of no representation without taxation in any serious way.
Another criticism of last Sunday's announcement was that it lacked detail. It may well be that Mr Kenny decided to make the announcement on the hoof for less than noble reasons. But even if that was the case, a lack of detail means that a debate on the specifics can take place without the government pushing for a pre-determined outcome, which is no bad thing.
The most important issue in that debate will be who qualifies. At its broadest, everyone with citizenship could be included. But this would be too broad because eligibility for Irish citizenship is more liberal than in many other countries (requiring as little as an Irish-born grandparent). And as the diaspora is so large, if everyone with the right to citizenship also had the right to vote, the electorate could expand by millions - and would include many people who have never set foot in Ireland and who may have no meaningful connection with or knowledge of the country.
Giving such people the same input into choosing the head of state as people who were born here and have lived here all their lives would be neither fair, nor reasonable.
Limiting the vote to those born in Ireland, but who have moved abroad, seems an altogether more sensible way to go. But even this may be too wide, as it would include people who may have moved abroad as children and never returned to the country over many decades. As such, a time limit of, say, 15 years after departure could be a starting point, with the possibility of extension in the future (via secondary legislation) if a consensus emerges to do so.
The one aspect of the Taoiseach's announcement last week that appears seriously problematic is the enfranchising of all citizens of Northern Ireland who are resident in that jurisdiction. This would not be a good idea.
A good reason to give members of the diaspora a vote is because, in many cases, they have no voting rights in their countries of residence - emigration has, in effect, meant disenfranchisement. That is not the case for those born in Northern Ireland and resident there.
Giving Northerners, who have full voting rights in the UK, a say in this state's presidential election would violate the principle of one person one vote.
This alone would not be a good enough reason to limit the extension of the franchise to all citizens of Northern Ireland. But there is an even more important reason to oppose it.
To give voting rights to a person who does not live in a given state, who does not identify with that state and who does not want to be part of that state does not make sense and comes with risks. This is not in any way to be hostile towards those on this island who feel, and therefore are, British.
It should also be said that while most Unionists want good relations between Northern Ireland and the Irish state, there is a minority which feels hostility towards the Republic.
Whether that sense of hostility is warranted or not is neither here nor there when it comes to the granting of voting rights - but to ignore it and its possible consequences would be imprudent.
At a time when the constitutional order of UK is weaker than it has been in decades, if not since the union with Scotland was formed three centuries ago, the North's political structures and relationships with the other nations on these islands may need to be renegotiated in the years to come.
If citizens of Northern Ireland were to have the right to vote in presidential elections, they would also have the right to exercise that right in whatever way they chose.
If a presidential election were to take place against a backdrop of unsettling change to the UK's constitutional order, it is not hard to envisage a scenario in which leaders of Unionism urge their followers to exercise that right in a manner that would maximise their leverage, and minimise Dublin's.
Most democracies grant to their non-resident citizens some form of voting right.
With Ireland's large diaspora, doing so would be a potent symbol of inclusion to those citizens who were born here but do not live here a say in presidential elections.
Extending that right to all citizens of Northern Ireland would, however, be a bridge too far.