Unionist politicians congratulated Boris Johnson on his election as leader of the Conservative party and incoming British prime minister, while nationalist and Alliance politicians wondered would he be a "statesman" or a "showman".
Mr Johnson's election also raised speculation about who might be the next Northern Secretary, with Michael Gove, who shafted Mr Johnson when he sought to become prime minister three years ago, mentioned as a possible Secretary of State for Northern Ireland.
The DUP leader Arlene Foster offered her congratulations and said she looked forward to discussing with Mr Johnson the "shared objectives of strengthening the union, delivering Brexit and restoring devolution".
She also suggested Mr Johnson would be making an early visit to the North. “I also look forward to welcoming Mr Johnson back to Northern Ireland shortly after he becomes prime minister,” she said.
Johnson has coasted into Downing Street on a wave of Brexit bluff and bluster
Sinn Féin deputy leader Michelle O’Neill said her party would “continue to work with the Dublin Government and the EU 27 to protect Ireland from the catastrophic impact of the reckless Brexit being pursued by Boris Johnson and the hard Brexiteers”.
“Sinn Féin will work to protect our peace process and the Good Friday agreement in all its parts, including the commitment to calling a referendum on Irish unity,” she added.
The SDLP leader Colum Eastwood said the election of Mr Johnson was a "worrying step toward a hard no-deal Brexit and a hard border in Ireland".
"Johnson has coasted into Downing Street on a wave of Brexit bluff and bluster. It won't be long until he crashes into the rocky reality that the European Union will not sacrifice the interests of Ireland to appease a man who has lied and slandered its institutions in an effort to secure power," he said.
The Ulster Unionist Party leader Robin Swann, in congratulating Mr Johnson, said he now faced "enormous responsibilities".
Alliance leader Naomi Long said what was required in the incoming prime minister was a "statesman, not a showman".
There is an expectation that Mr Johnson will move Karen Bradley – a Theresa May ally – from her post as Northern Secretary.
Mr Gove, a Leaver and firm unionist, probably would be a welcome appointment as far as most unionists are concerned
According to the Mail on Sunday and the Sunday Times, Mr Johnson is considering shifting Mr Gove from his environment post to the position of housing secretary or Secretary of State for Northern Ireland. Other names being mentioned for the North include the sacked former defence secretary Gavin Williamson and former Northern secretary Theresa Villiers.
Mr Gove, a Leaver and firm unionist, probably would be a welcome appointment as far as most unionists are concerned, while nationalists – and some unionists – would be dismayed by his views on the 1998 Belfast agreement.
In a pamphlet Mr Gove wrote in 2000, The Price of Peace – An Analysis of British Policy in Northern Ireland, he referred to the "wickedness" of the Good Friday agreement, describing it as a "moral stain" that would be hard to efface. One senior Sinn Féin source was sanguine about the possibility of Mr Gove moving to Northern Ireland. He said if Mr Gove did indeed get the job, he hardly could be less partisan than previous Tory holders of the post such as Owen Paterson, James Brokenshire and Ms Villiers.
Another senior source felt Mr Gove as Northern Secretary would be a problem. He noted that already there were questions over British government impartiality considering its dependence on the votes of the DUP’s 10 MPs.
He queried whether Mr Gove, with his Brexiteer and anti-Belfast Agreement opinions, was the Minister to push the DUP and Sinn Féin towards striking a deal to get the Northern Executive and Assembly functioning again.