The Progressive Conservative government is trying to rejuvenate after 10 years in power, three byelection defeats — two in districts that were Tory strongholds — and a drop in popularity.
But Coleman, a 60-year-old Corner Brook businessman, was the only Tory party leadership contender left Thursday after fisheries magnate Bill Barry cited a "stacked deck" and dropped out.
Coleman's family business includes Atlantic Canada's largest, family-owned independent grocery retailer. The eldest of eight children, and a father of seven, was already widely seen as the party's chosen candidate.
He has been endorsed by several cabinet ministers who chose not to run in a contest that drew just three contenders, all of them political outsiders.
Wayne Bennett was disqualified from the race after the party's rules committee found he made discriminatory comments on Twitter and failed to uphold party principles.
Coleman was not available for an interview but in a statement Thursday thanked Barry for running.
"While the circumstances of how I will become leader and premier have changed, I am no less humbled by taking on this very important role at a very critical time in our history," he said.
"I want to earn the trust, respect and support of the PC party and the people of this province. I will spend every day between now and the next provincial election demonstrating that it is the PC party with me as its leader that offers the best choice for the people of Newfoundland and Labrador."
Kelly Blidook, a political scientist at Memorial University of Newfoundland, said the Tories have missed a prime opportunity.
"When you're trying to build, one of the best things this party could have done would have been to have a real leadership convention.
"They've got one person showing up who looks like it was a fait accompli that he was going to be premier in the first place. I don't think it's going to help them much at all."
Premier Tom Marshall, who replaced Kathy Dunderdale in January on an interim basis until a new leader was to be chosen at a July convention in St. John's, said he was disappointed by Barry's decision.
"We were looking forward to a full and contested leadership race," he said in a statement. "Both Mr. Barry and Mr. Coleman were great candidates, and I wish Mr. Barry well."
Barry said he's abandoning his leadership bid and returning to private business as CEO of the Barry Group of companies. A complete lack of caucus support made him feel he was playing against a "stacked deck" with a preordained outcome, he added.
In recent days and weeks a growing list of Tory cabinet ministers endorsed Coleman.
That was after popular former premier Danny Williams, who stepped down to resume his business interests in 2010, publicly said he could not support Barry.
"I am encouraged to continue but I have to ask ... why would I, and why am I being encouraged?" Barry said in a statement early Thursday.
He said his ideas were not being heard, and that "my message of concern for our future appears to fly in the face of many recent policy decisions."
Bennett and Barry had both earlier raised concerns that Coleman had a lock on the leadership.
Several cabinet ministers who considered running for the top job counted themselves out, fuelling speculation that the caucus would back Coleman.
Tommy Williams, co-chairman of the party leadership convention committee and younger brother of Danny Williams, dismissed the suggestion.
"I don't think that's a fair comment," he said Thursday. "The leader of the party would be selected by 800-plus delegates at a convention had it been a contested race, so to suggest that it has been chosen by a small group of MHAs is not fair."
Williams said officials will discuss this weekend how the July convention will unfold.
"Obviously it won't be a contested convention, but we do have a date set to proceed," he said, adding a decision will likely be announced next week.
Under provincial law, an election must be called within 12 months of the new Tory leader being sworn in as premier.
— With files from Alison Auld in Halifax.
Follow @suebailey @alison_auld on Twitter.
Also on HuffPost