Brian Topp, left, and Ed BroadbentIf Thomas Mulcair chooses to vie for the leadership of the NDP he now faces an even tougher battle with Ed Broadbent's endorsement of Brian Topp on Monday.
In New Democrat circles, Broadbent is a godfather-like figure.
"In the NDP, when Ed Broadbent asks you to do something, you do it," wrote Stephen Maher in the National Post.
"The people who will decide this election — grassroots New Democrats across the country — will take Broadbent's endorsement very seriously."
In his column, Maher quotes MP Pat Martin who recounts the 2003 NDP leadership race where Broadbent backed Jack Layton when most of the caucus wanted Bill Blaikie.
"I remember how disheartened we were in Bill's camp in '03 when Ed endorsed Jack," Martin said. "We knew it was the Holy Grail of endorsements and would be very hard to overcome. Impossible, as it turned out."
Topp doesn't only have Broadbent's endorsement — it appears he also has the late Jack Layton's.
While Topp refuses to say whether Layton, prior to his death, had asked him to run, it's widely believed Topp was Layton's choice to succeed him.
"One can reasonably assume that if Layton had seen Mulcair — who would bring proven electoral success, cabinet experience and a Quebec household name to the fore of a leadership bid — as his natural successor, Topp would still be backstage running the party rather than auditioning for the lead opposition role in Parliament,"wrote Chantal Hebert in the Toronto Star.
Mulcair has also had to contend with some personal attacks from within the party.
Shortly after Layton's death, while analysts mused about leadership candidates, a New Democrat MP anonymously told the Hill-Times Mulcair is "difficult to work with." Another NDP insider said Layton's inner circle "loath" Mulcair.
Despite the set-backs and criticisms, however, Mulcair still seems intent to run.
Tuesday, flanked by other MPs at meeting of the Quebec NDP caucus, Mulcair hinted strongly the party would be making a mistake in not picking him given what was accomplished in the May 2 federal election which sent 59 Quebec MPs to the House of Commons.
"Jack Layton got us to a level that we've never seen before in the history of the NDP," Mulcair said. "I've been with him for the past five years, shoulder to shoulder, building that momentum here in Quebec.
"I'm encouraged because I've received hundreds of letters and emails and phone calls from people across Canada asking me to consider running for the leadership."
At least five other NDP MPs are mulling their chances. They are Nathan Cullen, Paul Dewar, Peter Julian, Megan Leslie and Peggy Nash.
Broadbent's endorsement of Topp, however, may just give them pause.
As for Mulcair - Bruce Hicks of Montreal's Concordia University likened his political style to that of a "street fighter."
In recent weeks, the "street fighter" has taken some blows. Whether he's ready to battle, remains to be seen.