Prime Minister Justin Trudeau is meeting with U.S. President Barack Obama and Mexican President Enrique Pena Nieto at the North American Leaders' Summit today. The remainder of Obama's presidency can be counted in months, while Pena Nieto, unpopular at home, will complete his single term in 2018.

Nevertheless, these two leaders present Trudeau with perhaps the best opportunity for continental co-operation — as their replacements could prove much less inclined to see eye-to-eye with the prime minister, particularly on the North American Free Trade Agreement (NAFTA). 

Of the Three Amigos, Trudeau is certainly in the strongest position. His term in office will continue until at least 2019 and likely beyond, as one-term governments are rare in Canada.

Three polls conducted over the last month have given him an average approval rating of 62 per cent and his Liberal Party the support of 47 per cent of Canadians. That puts him 18 points ahead of the opposition Conservatives.

Obama's approval ratings have greatly improved in recent months, as the president has perhaps looked better in comparison to the two unpopular candidates vying to replace him. Over 10 recent surveys, Obama has averaged an approval rating of 51 per cent, the highest it has been since February 2013, and a disapproval rating of 46 per cent.

But Obama's term in office will end in January, leaving him with little ability to accomplish much in the context of a volatile election campaign and in the face of a Republican-controlled Congress.

Pena Nieto will remain in office until 2018, and so still has some time ahead of him. But he is running out of political capital. Polling done in the spring by Grupo Reforma has pegged his approval rating at just 30 per cent, while another survey showed that two-thirds of Mexicans disagreed with his management of the country — the highest since he came to power in 2012.

But despite the limited means of these two — a U.S. president about to become a lame duck and a beleaguered Mexican president — they could be much better dancing partners for Canada than whoever might follow them.

NAFTA skeptics south of this border

Neither Hillary Clinton, the presumptive Democratic nominee, nor Donald Trump, the presumptive Republican candidate for president, speaks warmly of NAFTA. Trump calls it "a disaster," while Clinton says the agreement has "hurt a lot of workers."

The polls suggest Clinton is the favourite to succeed Obama. She is far less likely than Trump to demand a wholesale renegotiation (or revocation) of NAFTA, and may be playing to a domestic electorate attracted to the anti-NAFTA rhetoric of Bernie Sanders, her defeated but formidable Democratic primary opponent hailing from the left wing of their party.

Donald Trump, Hillary Clinton composite

U.S. presidential candidates Donald Trump and Hillary Clinton have criticized NAFTA. (Nancy Wiechec/Chris Bergin/Reuters)

She may temper herself while in office. Or she may not, particularly if she decides to listen to the American people. A Bloomberg/Selzer poll in March found that just 29 per cent of Americans thought NAFTA had been good for the U.S. economy, compared to 44 per cent who thought it was bad. A solid majority of Republicans felt it hurt the economy, but even among Democratic voters opinion was divided.

And though Trump is currently floundering in the polls, his chances of winning the presidency are certainly much better than zero. With his populist and isolationist policies in favour of trade barriers and physical barriers (along the border with Mexico), a Trump White House would have a profoundly negative impact on North American relations.

After Pena Nieto

​Mexican presidents only serve for one six-year term, so Pena Nieto cannot run for re-election in 2018. That vote is setting up to be a close contest among three candidates: one from Pena Nieto's Institutional Revolutionary Party (PRI), one from the National Action Party (PAN, the party of former presidents Vicente Fox and Felipe Calderon), and Andres Manuel Lopez Obrador.

One recent poll from El Financiero gave Lopez Obrador a narrow edge over the likely PRI and PAN candidates with 25 per cent support. A fiery left-winger, Lopez Obrador came up short by a few hundred thousand votes in the 2006 election (he contested the result) and finished second to Pena Nieto in 2012. Lopez Obrador has criticized NAFTA as causing job losses in Mexico.

Mexico Protest

Andres Manuel Lopez Obrador is a contender for the Mexican presidency in 2018. (Marco Ugarte/Associated Press)

Mexicans, however, support NAFTA. Polling by BGC/Excelsior from April pegged support for the treaty at 54 per cent, against 26 per cent who were not in support. According to this pollster, opposition to NAFTA has never topped more than 35 per cent of Mexicans.

But Mexican presidents are elected in a single round of voting, and Lopez Obrador could potentially prevail in a divided electorate. 

So Trudeau's window for getting things done within the North American context may be small. However, Pena Nieto doesn't have to worry about re-election. Similarly, Obama may be able to move things through the lame-duck Congress after the November election, when politicians are less fearful of voters' wrath.

But when these two leaders move into political retirement, things could get more complicated for the Canadian prime minister. Trudeau should enjoy the warm relations while they last, before the Three Amigos become the Three Enemigos.