How will Justin Trudeau affect Thomas Mulcair and the NDP?

NDP leader Thomas Mulcair's popularity will take a hit when Justin Trudeau announces his candidacy for the Liberal …Justin Trudeau is expected to announce on Tuesday that he will seek the leadership of the Federal Liberal party.

At this point, it's hard to believe that any other candidate could beat him in a leadership race, especially considering the party's new electoral rules which allow non-members to vote.

So, barring any surprises, the next election campaign will 'feature' Stephen Harper, Thomas Mulcair and Justin Trudeau.

Most pollsters and analysts believe that's bad news for the NDP.

Earlier this week, Abacus Data pollster David Coletto told Yahoo! Canada News that a Justin Trudeau-led Liberal party would cost the NDP a large chunk of support.

[ Related: Justin Trudeau 'a good candidate,' former PM Jean Chretien says ]

"We asked Canadians how they would vote if Trudeau was Liberal leader. Under a Trudeau leader scenario, the Liberals were statistically tied with the Conservatives and he would have taken 25 per cent of the NDP's vote," Coletto said.

"Trudeau would throw a wrench into the NDP's plans to consolidate the anti-Conservative vote while giving the Conservatives and the BQ some breathing room due to vote splitting in Ontario and Quebec."

Angus Reid's Mario Canseco also suggests there are troubled waters ahead for the New Democrats.

He cites a June 2012 poll that shows the NDP going from 35 per cent support to 21 per cent if Trudeau was Liberal leader.

Canseco, however, adds a couple of caveats: One, he says that this poll was done before the "NDP found its stride" and two, it might take time for Canadians to trust Trudeau with the keys to 24 Sussex.

"The likeability is there. The issue is whether he can turn this into votes. Jack Layton in 2006 and 2008 was, by far, the most "liked" leader, but he was unable to break through (with votes) until 2011," he told Yahoo! in an email.

"[The Liberals] may be going for an eight-year plan: have a decent showing in 2015, get some more seats, and then take a shot at forming the government in 2019. Justin's young enough to pull it off...This is the big question: can Justin succeed in taking a more "liberal" position on issues than what Mulcair would do?"

[ Related: Peter C. Newman: Trudeau's big leap - like father, like son ]

Thomas Mulcair, however, apparently doesn't buy the pollsters' 'pontifications.'

The takeaway from a Lawrence Martin story at iPolitics is that the NDP leader isn't too concerned about Pierre's son at all:

"Over dinner at Ottawa's trendy Metropolitain restaurant it's put to Mulcair that someone has arrived who could steal his thunder. Earlier in the day it was confirmed that Justin Trudeau would seek the Liberal leadership.

... Mulcair interrupts his oyster eating. "You know far too much about Quebec politics, " he says bluntly "to think that the Trudeau brand carries any weight in the province of Quebec."

As for policy, says Mulcair, before you get the keys to running this country, you have to have credibility on economic issues, his suggestion being that Trudeau lacks it."

Indeed, Trudeau will need to prove that he's got the intellect to match his charisma.

I guess we'll start finding out on Tuesday.