The emergence of Leo Varadkar as the next Taoiseach is a huge moment in the history of the Republic of Ireland, which is not yet 100 years old.
Mr Varadkar breaks new ground for Ireland, in two respects.
He is gay, and so still one of the few prime ministers in Europe to have been openly so, and the first in the Republic.
He is also the son of an immigrant Indian doctor, and thus of part of his heritage is significantly different from the traditional Irish Catholic background that dominated the Dublin establishment first century of the Republic.
The south has become radically less monocultural in the last 25 years than it was in its opening decades.
In the years before the Great War, unionists for good reason talked about Home Rule being Rome Rule.
The first half century of the independent Ireland proved unionist fears, when it was every bit as dominated by the Catholic Church as Protestants had predicted it would be.
But the decline of the influence of the church began slowly in the 1960s, then accelerated rapidly in the 1990s.
Unionists ought to be able to build strong relations with a politician such Mr Varadkar – and they badly need to build relations with a range of moderate politicians in Dublin, given the cynical and destabilising way that Sinn Fein is behaving.
Fine Gael, while it has had some very nationalist and anti-unionist politicians over the years, has generally been more sensible about Northern Ireland than Fianna Fail has been.
Mr Varadkar is rightly talking about how problematic it will be for the Republic if unity somehow scrapes the support of 51% of the people in Northern Ireland. Sinn Fein mouths similar concerns but shows in its actions that it is only interested in triumphalism and the defeat of unionists.
Unionists must engage with Irish leaders who are genuinely concerned about the unlikely, but possible post-Brexit, scenario of a sudden and rushed vote for unity.
Doing so can help to make that scenarios a little less likely.