The upcoming week and success in the byelections pose a real challenge to Justin Trudeau’s team.

They say only Nixon could go to China. Justin Trudeau reminded us this week that, sometimes, others shouldn’t even try. But for all the tongue-clacking and tweeting about the Liberal leader’s so-called gaffe, it’s the upcoming week that should be concerning to Trudeau’s team. Success in the byelections, not his Asiatic slip-up, is the real challenge that lies in wait.

On Nov. 25, voters in four ridings will send new MPs to Ottawa. In Toronto Centre and Bourassa, Liberals look to retain important urban seats, notwithstanding a full-out assault from the NDP. Further west, Brandon Souris and Provencher were supposed to be easy holds for the governing Conservatives. Only one will be.

Shockingly, Brandon appears to be in play with Trudeau’s Liberals looking for a steal at Stephen Harper’s expense. Wise money would still bet on a narrow Liberal loss, but if perception is reality in politics, the reality is that next Monday could be a tough day for the prime minister.

He won’t be alone. For Tom Mulcair, the failure to break through and demonstrate that he, not Trudeau, should be regarded as Harper’s legitimate alternative will prove excruciating. Each result will sting. Toronto Centre will rob him of bragging rights in a high-profile showdown.

Bourassa is a key test of his ability to win on the Island of Montreal in a riding near his own. And Brandon Souris will suggest that when voters do conclude it’s time for change, it is to the Liberals, not the NDP, they will turn. Spin will be spun on election night. But the fact is that it will be a grave disappointment for Mulcair.

The leader most challenged by the results, however, will be Trudeau. He will awaken next Tuesday morning a changed man, living under the weight of changed expectations. He will — for at least a time — be the undisputed challenger, the charity boxer who will have won the title of No. 1 Contender for the decorated belt of prime minister.

This is, it should be noted, what the Liberals have wanted, what they have sought. It is the first of a twostep strategy to win the 2015 election: overtake Mulcair first, then confront Harper as the consolidated option for those seeking change.

But it also plunges Trudeau into new political territory — ground that is more exposed and, by extension, more perilous. A bright spotlight will become even brighter. Attacks from his opponents will become sharper.

Demands from a curious electorate will grow greater. He will now be required to rise to the moment he has made for himself and launch the transformation from political wunderkind to would-be prime minister.

Endless prescriptions will soon be volunteered by all and sundry. Most will urge that he drape himself in heavier policy garments. But it’s not really a policy test that Trudeau is set to face.

It’s a credibility test. And sensible policy positions will form only part of his matriculation. Yes, he will have to do more than declare “I’m for the middle class.” A sharpened and shareable economic message is a must. But we all already knew that. The less remarked-upon goal will be finding fresh ways to keep accumulating political capital.

Both by accident and design, Trudeau has spent the past two months drawing from this reservoir rather than enlarging it.

The intriguing choice to go to Washington and advocate for the Keystone pipeline will stand him well in the long run. It is the sort of move that adds to his resume as a national leader. But make no mistake, it will be used by the NDP to peel away green-hued voters. That equals depletion.

Similarly, the new ad in which he’s featured does little to broaden his base. At best, it gives voters more of what they want: Justin. But it’s the least enticing presentation of him we’ve yet been offered. Not quite substantive but neither his usual dynamic self. It is, in a word, boring. He supports the ad, instead of the other way around. And then there’s China — not the end of the world that some suggest, but hardly helpful. With 24 months left to go, Trudeau will need to find new ways to build muscle and momentum — ongoing success at fundraising and candidate recruitment, a response to Harper’s balanced budgets and middle-class tax cuts and the delineation of priorities to define both this new Liberal Party and its old opponents.

To make matters even more challenging, he must avoid the appearance of abrupt adjustment. He cannot dare afford to stop being himself — that vital thing that people appear to be responding to with such enthusiasm. Even as he works to expand the public’s willingness to see him in the elevated role of Canada’s first minister, he must hold on to what he’s got going on.

The goal is to ripen his political identity, not depart from it. So no more flat-as-plywood advertisements. No more confusing stiff and static with sensible and sagacious. The man is a thoroughbred and Seattle Slew shouldn’t be asked to pull a sulky.

With next Monday’s byelections, Trudeau is on the brink of his greatest political accomplishment to date. For his trouble he will receive an equal-sized dose of political challenges. Forget China. Winning is about to test Justin Trudeau in a way that screwing up never could.