It's been quite the run-up already to the federal NDP's leadership contest, especially when you consider the race to succeed Tom Mulcair won't officially begin for another three weeks.

Start with the potential candidates who've indicated they won't be running. All of them capable. All of them with the kind of name recognition a leadership race needs.

​There's Nathan Cullen, the popular British Columbia MP who ruled himself out a week ago. Then there's Brian Topp, chief of staff to Alberta Premier Rachel Notley, who finished second to Mulcair four years ago.

And finally, Megan Leslie, the former MP from Halifax who lost her seat but not her standing inside the party.

Then add Cheri DiNovo, the Ontario MPP who declared this week that she's an "unofficial candidate" because she's really interested in making a point about the unfairness of the $30,000 registration fee she doesn't have, and would step aside from her unofficial campaign if somebody stronger came along.

Ontario MPP Cheri DiNovo says she's an 'unofficial candidate' and wants to make a point about the unfairness of the $30,000 registration fee. (Martin Trainor/CBC) "I'm running for principles, not for a position," she said.

Fair enough. But principles need a principal. A leader capable of advancing those causes DiNovo actually identified in her news conference: a secure place for the marginalized in society, justice for minorities and more generous social benefits.

Someone, unlike DiNovo, who can and will come up with the money needed to enter the race.

In search of a leader

Longtime NDP strategist Sally Housser is confident those people will emerge once the race officially begins on July 2.

"There are still a number of very, very serious and excellent candidates out there," she said on the CBC's Pollcast this week.

But New Democrats aren't just in search of a leader, they're in search of ideas and a way to rebuild a voting base at least partially dismantled by the Liberals in the 2015 election.

There are two possible routes.

The first is to try to mimic the success of Notley in Alberta, whose government married the pro-environment message with the pro-pipeline position of the province's most powerful unions.

The other is the kind of bold action contemplated in the Leap Manifesto, which cleaved a wedge into the NDP convention in Edmonton that swallowed Mulcair. It calls for a basic annual income for all Canadians, an end to all fossil fuel consumption by mid-century and an end to trade deals that interfere with Canada's ability to regulate corporations and control local economies.

The NDP is exploring the ideas in the Leap Manifesto, and some members think the party's future depends on adopting at least some of them to galvanize those marginalized Canadians that DiNovo identified.

And here's why.

The Liberals, under Prime Minister Justin Trudeau, staked a claim to significant portions of the NDP's progressive base in 2015, a base that includes women, union members and environmentalists.

Since taking power, the Liberals have worked hard to solidify that support.

Liberals move quickly

Trudeau's cabinet is split half and half between men and women. His government is poised to announce its promised inquiry into missing and murdered Indigenous women.

The Liberals moved quickly to repeal Conservative legislation that compelled unions to disclose how members' dues are spent and made it harder to organize federally regulated workplaces. The Liberals stood by their pledge to run deficits to pay for a multibillion-dollar infrastructure program with all the jobs that would create.

The Liberals have moved quickly to secure their gains among progressive voters, including standing by their pledge to run deficits to pay for a multibillion-dollar infrastructure program. (Paul Chiasson / Canadian Press) And work has begun with the provinces to establish national emission-reduction targets.

These are the kinds of progressive issues the NDP has long championed, initially as a social democratic movement and then, under Jack Layton, as a political party increasingly seen as a viable alternative to the Liberals and Conservatives.

They are the kinds of issues Tom Mulcair continued to promote in the 2015 campaign: universal $15-a-day child care, a national cap-and-trade program to combat climate change, and a similar commitment as the Liberals to hold an inquiry into missing and murdered Indigenous women.

We all know the result. The NDP was reduced to 44 seats, a respectable but still deeply discouraging result when the Liberals surged past them — in no small measure thanks to support from people who voted NDP just four years earlier.

Need to attract young voters

Sally Housser believes the party has to re-imagine itself at the federal level to attract young voters, members of the LGBTQ community and the working poor.

"We just can't keep doing the same things, the same way over and over again," she said in an interview. "For a long time, New Democrats believed young people came to us. That union members came to us. I don't see the evidence of that anymore."

Former New Democrat MP Andrew Cash has already begun that work through the Urban Worker Project. It's trying to mobilize Canadians who work in part-time, freelance and other self-employed positions to obtain better health and dental benefits, better parental leave, more affordable housing and work space.

NDP strategist Sally Housser believes the party has to re-imagine itself at the federal level to attract young voters, members of the LGBTQ community and the working poor. (The Canadian Press) Others inside the party suggest that more must be done to earn the support of women in lower-income families, particularly those who are the main breadwinners, who don't benefit from the Liberals' middle-class tax cut.

These are the kinds of progressive ideas that excite many inside the NDP. They are the kinds of things that might help distinguish New Democrats from the Liberals as the party prepares to embark on its leadership race.

What they need now are candidates prepared to run for principles, and for the position.