New climate facing Mary Lou McDonald
Mary Lou McDonald, who was selected unopposed at the weekend as the new president of Sinn Féin, has taken on the post at a time of considerable opportunities and risks within Irish politics in the north and south.
She will be well aware that, if events move in a certain direction, her party could shortly be sitting in government in both Belfast and Dublin, with the Brexit upheaval simultaneously making the broad nationalist goal of Irish unity by consent an increasingly achievable objective in the foreseeable future.
However, she knows it is also possible that the Stormont institutions could soon be indefinitely suspended, Sinn Féin may be outmanoeuvred by other inter-party deals in the Dail and tensions between the UK and EU authorities might result in the nightmare prospect of a hard border in Ireland.
There is all to play for in the coming months, and, while Sinn Féin has its own mandate, it is evolving relationships with other parties and the British and Irish administrations which are likely to prove crucial.
Ms McDonald has the considerable advantage of coming into her role without any paramilitary links, and should be in a reasonable position to develop understandings among nationalists on both sides of the border while hoping that unionists will also respond to her approaches.
She will be aware that Sinn Féin, with 28 pc of the vote in the 2017 Assembly poll, and 14 pc in the 2016 Irish general election, has managed significant advances under Gerry Adams but is nowhere close to the level of support required to progress its policies without the assistance of others.
In the past, when the long shadow of the IRA so closely connected to Mr Adams was hanging directly over the party, there was no serious prospect of it entering coalition arrangements in Leinster House.
Ms McDonald comes from an entirely different background to her long-serving predecessor and, as been well documented, grew up in the residential Rathgar district of south Dublin, attended a fee-paying school and joined Fianna Fail before switching to Sinn Féin.
She has established herself as a particularly capable performer in the Dail, both on scrutiny committees and in the main chamber, and will be widely regarded as a potential tanaiste after the next Irish election.
Internally within Sinn Féin, she must find ways of addressing the damage caused by the mishandled Barry McElduff case, the sharp contradictions over salaries paid to elected representatives and the concerns over allegations of bullying in sections of the party.
What is essential is that she works closely with other pro-EU groups across Ireland to ensure that aggressive border controls, which are completely unacceptable to nationalists and, whether they realise it or not, hugely damaging to unionists, are avoided.
The reality is that the Brexit issue has fundamentally transformed Irish politics, and Ms McDonald and all our other party leaders find themselves operating in a rapidly changing climate which will allow fresh options to emerge sooner rather than later.