OTTAWA -- The flip side to the "Where's Joe Oliver?" campaign refrain these days is, "Here's Michelle Rempel," or "Voila Erin O'Toole."

While Oliver, the finance minister, might be taking a noticeably lower profile during the election, as is Foreign Affairs Minister Rob Nicholson, other Conservative incumbents are appearing comfortably in front of national TV cameras and campaigning on behalf of other candidates.

They are quite possibly the next top-tier of cabinet, or else the front bench of a future opposition shadow cabinet. They include Rempel, a junior minister for western economic development; Veterans Affairs Minister O'Toole; and Immigration Minister Chris Alexander -- the latter's star having taken a hit over his handling of the Syrian refugee crisis.

Other more veteran ministers, including Rona Ambrose, Tony Clement, Lisa Raitt and Maxime Bernier have also been doing work outside of their own ridings.

And then there's Defence Minister Jason Kenney -- besides Leader Stephen Harper, the only Conservative politician who can speak for the campaign as a whole. In Quebec, Denis Lebel has earned the same type of license.

Harper has never been much for succession planning or profiling a Conservative "team", but this campaign could also be serving as a showcase of the leadership potential inside the party. The politicians involved are fortifying links at the riding level, and with future caucus colleagues.

Of course a renewal in the Conservative cabinet ranks is inevitable, with a number of senior ministers not running this time. The industry and justice portfolios, for example, are held by Conservatives who are leaving office. If Harper loses the election, leadership becomes an immediate consideration.

The new generation of Conservative standard bearers are all regarded as good communicators within the party.

Last week, Rempel succeeded in doing something politicians dream of -- knocking a rival squarely off her talking points tightrope.

"Which tax loophole are you going to close Jennifer, which one, and how much is it going to affect the budget?" Rempel challenged NDP candidate Jennifer Hollett on CBC's Power and Politics program. The NDP's fiscal plan promises to save money through plugging tax loopholes.

Hollett, visibly flummoxed, responded awkwardly that, "I'm here to talk about the debate last night."

Where some Conservative candidates have avoided the media during the election, O'Toole has made himself accessible to respond to questions on the veterans affairs file, and recently penned a defence of his government's policy record with Huffington Post Canada.

This week, he's making an announcement on veteran's policy in New Brunswick on behalf of the entire campaign. O'Toole was elected in November 2012 following a byelection.

"All parties should want to be replenishing their benches with good people. That's good organizational management and it's good political management," said Regan Watts, a former senior ministerial aide and Conservative activist.

"I think that's certainly part of the equation. Whenever new faces come to politics, especially Erin with his pedigree as a military vet and a lawyer, those are the kinds of people you want."

Kenney remains one of the leading figures in the Conservative "secondary" campaign, going from riding to riding across the country to rally candidates and meet with community groups. It's a role he played with great success in 2011, as the Conservatives swept up seats in the Greater Toronto Area.

Early this week, he hopped between candidates' meetings in the area around Hamilton, Ont. and nearby Halton. Travelling has presented seemingly little risk for Kenney, as he has won by a landslide in every election since 1997.

Michelle Austin, a senior adviser with Ottawa consulting firm Summa Strategies, said Rempel and others who travel are providing a big service to the party by motivating candidates and their teams.

"New candidates' number one question is often, 'Am I doing this right' when they knock on doors," said Austin, a former chief of staff to both Bernier and Ambrose.

"They need reassurance that they are delivering well as a candidate, and also in terms of the party's messages."