In Canada, the governing centre-left Liberals had trailed the Conservatives by more than 20 points in January, but now lead by five points and are likely to win a majority of seats at next Monday's election. Meanwhile, United States President Donald Trump's ratings in US national polls have dropped to a -5 net approval.

The Canadian election will be held next Monday, with the large majority of polls closing at 11:30am AEST Tuesday. The 343 MPs are elected by first past the post, with 172 seats needed for a majority.

The Liberals had looked doomed to a massive loss for a long time. In early January, the CBC Poll Tracker had given the Conservatives 44% of the vote, the Liberals 20%, the left-wing New Democratic Party (NDP) 19%, the separatist left-wing Quebec Bloc (BQ) 9%, the Greens 4% and the far-right People's 2%. With these vote shares, the Conservatives would have won a landslide with well over 200 seats.

At the September 2021 election, the Liberals won 160 of the then 338 seats on 32.6% of votes, the Conservatives 119 seats on 33.7%, the BQ 32 seats on 7.6%, the NDP 25 seats on 17.8%, the Greens two seats on 2.3% and the People's zero seats on 4.9%. he Liberals were short of the 170 seats needed for a majority.

The Liberal vote was more efficiently distributed than the Conservative vote owing to the Conservatives winning safe rural seats by huge margins. The BQ benefited from vote concentration, with all its national vote coming in Quebec, where it won 32.1%.

On January 6, Justin Trudeau, who had been Liberal leader and PM since winning the October 2015 election, announced he would resign these positions once a new Liberal leader was elected. Mark Carney, former governor of the Bank of Canada and Bank of England, was overwhelmingly elected Liberal leader on March 9 and replaced Trudeau as PM on March 14.

With the Liberals short of a parliamentary majority, parliament was prorogued for the Liberal leadership election and was due to resume on March 24. Carney is not yet an MP (he will contest Nepean at the election). Possibly owing to these factors, Carney called the election on March 23.

In Tuesday's update to the CBC Poll Tracker, the Liberals had 43.1% of the vote, the Conservatives 38.4%, the NDP 8.3%, the BQ 5.8% (25.4% in Quebec), the Greens 2.2% and the People's 1.4%. The Liberals have surged from 24 points behind in early January to their current 4.7-point lead.

Seat point estimates were 191 Liberals (over the 172 needed for a majority), 123 Conservatives, 23 BQ, five NDP and one Green. The tracker gives the Liberals an 80% chance to win a majority of seats and a 15% chance to win the most seats but not a majority.

The Liberal lead over the Conservatives peaked on April 8, when they led by 7.1 points. There has been slight movement back to the Conservatives since, with the French and English leaders' debates last Wednesday and Thursday possibly assisting the Conservatives.

But the Liberals still lead by nearly five points in the polls five days before the election. With the Liberals' vote more efficiently distributed, they are the clear favourites to win an election they looked certain to lose by a landslide margin in January.

Carney's replacement of Trudeau has benefited the Liberals, but I believe the most important reason for the Liberals' poll surge is Trump. Trump's tariffs against Canada and his talk of making Canada the 51st US state have greatly alienated Canadians and made it more difficult for the more pro-Trump Conservatives.

In an early April YouGov Canadian poll, by 64-25, respondents said the US was unfriendly or an enemy rather than friendly or an ally (50-33 in February). By 84-11, they did not want Canada to become part of the US. If Canadians had been able to vote in the 2024 US presidential election, Kamala Harris would have defeated Donald Trump by 57-18 in this poll.

In Nate Silver's aggregate of US national polls, Trump currently has a net approval of -5.4, with 50.8% disapproving and 45.4% approving. At the start of his term, Trump's net approval was +12, but went negative in mid-March. His ratings fell to their current level soon after Trump announced his "Liberation Day" tariffs on April 2.

Silver has presidential approval poll data for previous presidents since Harry Truman (president from 1945-53). Trump's current net approval is worse than for any other president at this point in their tenure except for Trump's first term (2017-2021).

Silver also has a net favourability aggregate for Elon Musk that currently gives Musk a net favourable rating of -13.6 (53.0% unfavourable, 39.3% favourable). Musk's ratings began to drop from about net zero before Trump's second term commenced on January 20.

G. Elliott Morris used to manage the US poll aggregate site FiveThirtyEight before it was axed. He wrote last Friday that Trump's net approval on the economy (at -5.8) is worse than at any point in his first term. During his first term, Trump's net approval on the economy was mostly positive, helping to support his overall ratings.