Image copyright EPA

Young, charismatic and centre-left. If Justin Trudeau in 2016 reminds you a bit of Barack Obama in 2009, that's not surprising. But can Trudeau fulfil the Obama promise better than Obama himself? Canadian writer Jordan Michael Smith has doubts.

Canadian Prime Minister Justin Trudeau will almost surely get along better with US President Barack Obama than his father, Prime Minister Pierre Trudeau, did with President Richard Nixon.

Nixon called Trudeau by a vulgar anatomical slur, tapes that emerged during the Watergate hearings revealed.

According to his memoir, when Trudeau heard this insult, he quipped: "I've been called worse things by better people."

But Justin and Barack have more in common than Pierre and Dick ever did. They are both young celebrity politicians, centre-left on the political spectrum. But those who believe the like-mindedness and obvious affection between the two leaders will usher in a new era of cross-national liberalism are likely to be disappointed.

Just as many Democrats are disappointed in the limits of Obama to bring progressive change to America, anyone hoping Trudeau will realise Obama's promise, that he could do for Canada what Obama was unable to do for America, will be similarly disillusioned.

Image copyright Everett Collection Historical / Alamy Image caption Richard Nixon and Pierre Trudeau during Nixon's visit to Canada in 1972

At first glance, it would seem that Trudeau has better chances of being a new FDR in ways Obama couldn't. Canada's parliamentary system, based on the British model, gives a prime minister powers the likes of which an American president can only dream.

That's because members of parliament are far weaker in relation to the PM than members of Congress are to the president.

Obama, by contrast, has been stymied by Congress on everything from immigration reform to closing Guantanamo Bay.

Though relations between presidents and Congress are particularly hostile in our hyper-polarised era, the American system has more built-in checks and balances - what political scientists call "veto points" - than the British-Canadian one. That simply makes it harder to get things done in any situation.

But precisely because the Canadian political system makes it easier to pass legislation of any kind, Canada has already passed many progressive laws, implementing programmes that are non-existent in the US.

America lags behind other developed countries in health care coverage, maternity and paternity leave, unemployment benefits and many other measures of equality.

Image copyright Reuters Image caption The difference in governmental structures between Canada and the US make for different political realities

This isn't for a lack of liberals and Democrats trying to get such legislation passed - it's because they have been unable to.

So there is simply much less to be accomplished by Canadian liberals than their American counterparts. Certainly, there are items on the Liberal Party's wish list - reforming the electoral system, investing in clean energy, normalising relations with Iran, and creating an advisory board for Senate appointments.

But this is hardly the stuff of drama. When Obama took office, he had pledged to end two wars, pass healthcare reform, end the power of lobbyists and reverse the Great Recession through a massive government spending package, among many other monumental tasks.

Liberals had more hopes for Obama because there was simply much more for him to do.

Obama lavishes praise on Trudeau

Is the US experiencing Trudeaumania?

What Canadians make of the US election

There is another reason Trudeau will not be a progressive Canadian saviour. Progressives in Canada have another alternative.

The New Democratic Party (NDP) is more left-wing than Trudeau's Liberals.

Where the NDP opposes the Keystone XL pipeline, the Liberals support it. The NDP wants mandatory cap-and-trade policies, while the Liberals call for voluntary standards (although this might be changing). The NDP wants Canada out of Iraq, while the Liberals advocate for remaining to train Iraqi soldiers.

These are just some of the ways in which the NDP is more progressive than the Liberals. Those who want a more progressive Canada don't have to support Trudeau. He doesn't espouse the country's most left-wing ideas.

Image copyright Reuters Image caption New Democratic Party leader Thomas Mulcair represents the most-left major party in Canada

Conversely, progressives in America's two-party system have no viable alternative to the Democrats. As Senator Bernie Sanders is showing, left-wing politicians in the United States can occasionally draw support.

But they are rare, and they have little institutional or financial backing, making their sustainability all but impossible.

The last remotely nationally popular left-wing party in the US, the Green Party, gained not even 3% in the 2000 presidential election. Even worse for those hoping to strengthen the American Left, many analysts credit the Green Party with attracting vital votes from the Democrats in that election, leaving the country with a Republican president named George W Bush.

That doesn't mean Trudeau cannot accomplish anything. Indeed, he already has.

Aside from bringing Canada international attention it has not received since Toronto Mayor Rob Ford was caught smoking crack cocaine, since coming to power in October, Trudeau increased the number of Syrian refugees it would permit into Canada, appointed the most diverse cabinet in the country's history, enacted more progressive taxation, and ended the country's support for US bombing campaigns against the so-called Islamic State groups.

Those are all important initiatives, and policies progressives can cheer. They simply aren't on the world-shaking level of Bernie Sanders' call for a "political revolution". That will keep Trudeau from being a historical icon of liberalism, no matter how good he looks.

Jordan Michael Smith, a Canadian writer living the United States, has written for the New York Times, Washington Post, and the Toronto Star.