By the standards of Daniel O’Connell’s ‘monster meetings,’ the ‘Ireland’s Future’ event at the Waterfront Hall last Saturday was a modest affair.

Judged by the yardstick of modern political campaigning, however, this was the most important political gathering in Ireland for two decades.

In coming years, ‘Beyond Brexit: The Future of Ireland’ will be remembered as an inflection point. O’Connell may have pulled in hundreds of thousands, but a combination of print, broadcast and social media coverage has carried the message from Saturday even further.

My Twitter feed has not stopped pinging for the last 48 hours with people tweeting and retweeting snippets about the day. There was also blanket media coverage across Ireland and everyone who attended this remarkable event – around 2,000, according to the BBC – left energised with a real sense of possibility.

Everyone felt it. Three party leaders, a senior Irish government minister and the deputy leader of the main southern opposition party is quite a haul. Notwithstanding the fact they are usually at each other’s throats. Yet here they were, the cream of Irish politics, sat in this cavernous space, many of them mere delegates, clapping and retweeting each other’s points.

Something has changed, with Brexit catalysing Irish politics into a renewed purpose. I’ve been to scores of political conferences over the years, but there was something different about Saturday’s event. I remember campaigning in the Good Friday Agreement referendum with young members of the SDLP, Sinn Féin as well as Fianna Fáil and Fine Gael. I would class Saturday’s event in that vein, with a similar sense of goodwill and shared endeavour.

Clearly, the day served as a focal point for the rising anger among nationalists and political progressives about Brexit and the various failings of the DUP and the fact that devolution is mired – but there was no rancour and little rhetoric.

Instead, we heard a series of speakers make telling and entirely valid points about the economic dangers of Brexit, the slow progress in obtaining civil and human rights and about how we must uphold the Good Friday Agreement settlement.

I mentioned a couple of years ago the need to ‘deshinnerise’ the issue of Irish unity in order to broaden and deepen its appeal, particularly among Irish political elites. Well, Saturday showed this is well in hand, as speaker after speaker either called for it, mentioned it, or touched on it.

As I said at the event, the day bookends, for me, the first part of the journey toward a united Ireland: We are all now talking about it. There is no more sidling around the issue.

Finally, in no particular order, here are my other quick takeaways from the day:

1. The involvement of the southern establishment. Dublin, no doubt inspired by the unfolding disaster around Brexit, is now much more serious about its all-Ireland responsibilities. The message was clear: the Irish Government will not leave people in the North behind.

2. Middle-class nationalists are now in play. The striking tone of the day came from a succession of speakers from the constitutional nationalist tradition, who, while not politicians, brilliantly articulated the frustrations that have developed in recent years – particularly around the struggle to get Unionism to accept parity of esteem. One of the event’s organisers, solicitor Niall Murphy, summed up the feeling when he said that nationalism ‘is looking beyond the parameters of the Northern state.’ Brexit, he said,’ has changed everything.’

3. Brexit, the failures of the DUP – and Irish unity – are now part of the same core narrative. The first is, in part, caused by the second, while the third is the answer to being relieved of both. Irish unity is the way out of the Brexit quagmire and a release from the need to formally share power with a party whose better angels most people at the event have now given up trying to locate.