In sacrificing personal ambition for the sake of his party, Bob Rae has opened the Liberal leadership race to new voices, new ideas, and possibly a new generation.
The immediate question is whether Justin Trudeau will put himself forward as the face of that new generation, or whether lesser-known figures will fight for the legacy of a once-great party now mired in third place.
The more lasting question may be whether a new leader with a new vision can arrest the threat that the Liberals will slide into irrelevance in a country that is polarizing into a stark conflict between left and right.
Mr. Rae told his caucus on Wednesday that he would stay on as interim Liberal leader until a new permanent leader is chosen.
"The way in which I can serve my party best is by not running for the leadership," he told reporters afterward.
"It hasn't been an easy decision," Mr. Rae acknowledged. All quarters, within the party and without, had expected him to run. The party's national board of directors decided when it met by teleconference on Wednesday evening that the leadership vote will be held in April, 2013. It had expected that its task would be releasing Mr. Rae from his commitment not to seek the permanent job.
But Mr. Rae pre-empted that decision – not, he said for personal reasons or because, at 63, he thought himself too old for the job.
Instead, he said, his earlier pledge that he would not use the interim position as a springboard for the permanent leadership "was a reality that needs to be respected."
He must also have been aware that internal divisions were once again threatening to recreate the factional bitterness that plagued the Liberal Party for decades.
One faction, citing Mr. Rae's experience, competence and high profile, saw him as the only person who could lead the party out of its current slough of meagre popular support, inadequate fundraising and organizational sclerosis. Up to a third of Liberal riding associations are thought to be effectively moribund.
Another faction was convinced that Ontario voters would never forgive or forget Mr. Rae's record as the province's NDP premier, which ended with his decisive defeat in 1995.
Rather than fight such a bitter battle, Mr. Rae chose to step aside.
Darrell Bricker, president of Ipsos Reid Public Affairs, said the party "should be very grateful" that Mr. Rae decided not to run. His decision, he said, affords Liberals an opportunity to seek a new generation of leadership with a new vision for the party.
Mr. Trudeau is the most obvious candidate. The Montreal MP possesses not only the name of his father, former Liberal prime minister Pierre Trudeau, but some of his charisma as well. He is a passionate advocate of a more socially inclusive federation in which Quebec, once again, would be a vital force on the national stage.
But many Liberals worry, with good reason, about the party's Messiah complex: its endless search for the leader who will magically return it to its glory days as Canada's natural governing party.
And Mr. Trudeau has repeatedly said that he does not want to run, citing the need to spend time with his wife and young children.
"My decision is a sign of my own reflection and my family reflection," Mr. Trudeau told The Globe and Mail, "and my decision is a no, still."
A larger question might not be who should lead the Liberals, but what the party should stand for. With the troubled economy dominating all other considerations in voters' minds, politics at the national level is dividing into an ideological contest between the Conservatives – who, under Stephen Harper, stress low taxes, open trade and an expanded natural resource sector – and the NDP – which, under Thomas Mulcair, argues that the Tory approach is damaging both the environment and manufacturing jobs in Central Canada.
The danger for the Liberals, Mr. Bricker said, is that their voice could be lost in the din.
"Without a significant rebranding, a significant reorientation, significant new ideas, and a new splash, they're just going to continue on this steady track down," he said.
Rebranding the Liberal Party will be the great challenge for whoever would lead it. In stepping aside, Bob Rae has opened the door to that recreation.