In 1971, 69 per cent of Americans told Gallup, a pollster, they would vote for their party's candidate for president if he were black. It took 37 years, but it finally happened with the election of Barack Obama as the U.S. president in 2008.

In 2017, 69 per cent of Canadians told the Angus Reid Institute they would consider voting for a party led by a Sikh man. Jagmeet Singh, the new leader of the New Democratic Party and a practising Sikh, will have to overcome that sentiment much more quickly to become prime minister.

The poll, conducted in the wake of Singh's leadership victory on Oct. 1, found 31 per cent of respondents would not vote "for a party led by a Sikh man who wears a turban and carries a kirpan," regardless of what policies he espoused.

The example of the United States shows how opinions can be slow to change, as Gallup's polling indicates it wasn't until the late 1990s that more than 90 per cent of Americans were comfortable with voting for a black presidential candidate.

It suggests that Canada could have a long way to go before the first non-white leader of a federal party is accepted by all but a small segment of the population.

Former U.S. president Barack Obama speaks on Sept. 20 in New York. Gallup's polling indicates it wasn't until the late 1990s that more than 90 per cent of Americans were comfortable with voting for a black presidential candidate. Obama won the 2008 and 2012 elections. (AP Photo/Julio Cortez) In 2007, the year before Obama won the Democratic primary and subsequently the presidential election, 94 per cent of Americans said they would vote for a black man.

Canadians are not much different from their southern neighbours. A poll conducted by ARI in June also found 94 per cent of Canadians would consider voting for a party with a black leader. The same poll found that 56 per cent could vote for a party led by a man wearing a religious head covering. Among Americans, it was only a little lower at 53 per cent.

But this does not necessarily mean Singh will have to wait long to achieve his goal.

'I am not the Catholic candidate'

Religion was a significant factor in the 1960 U.S. presidential campaign as John F. Kennedy, the Democratic nominee, was a Roman Catholic. In May 1960, only 71 per cent of Americans told Gallup they could vote for a Catholic candidate.

Kennedy was forced to address the issue, declaring that "I am not the Catholic candidate for president. I am the Democratic Party's candidate for president, who happens also to be a Catholic. I do not speak for my church on public matters, and the church does not speak for me."

Former U.S. president John F. Kennedy listens to a speech outside the White House in 1963. In May 1960, only 71 per cent of Americans told Gallup they could vote for a Catholic candidate. That November Kennedy won a close race after declaring, 'I am not the Catholic candidate for president.' (Associated Press) Kennedy narrowly prevailed over Richard Nixon. In 1961, when Gallup next asked about whether Americans would vote for a Catholic, the percentage who said yes jumped 11 points to 82 per cent. It reached 90 per cent by 1967.

Singh will have to overcome both religious and racial prejudice to pull off the same feat in so short a time. But religion is certainly a factor in the discomfort recorded by ARI — particularly in Canada. In June, the pollster found 65 per cent of Canadians could vote for a party led by an evangelical Christian, 15 points fewer than those who could vote for an atheist.

In the United States, an evangelical Christian was acceptable to more respondents than an atheist by a margin of 20 points.

NDP win seen less likely than a Sikh PM

The party that Singh heads has a history of choosing groundbreaking leaders. David Lewis, who become the NDP's second chief in 1971, was the first Jewish leader of a federal party. He chose not to run in the party's first leadership campaign 10 years earlier because "I wasn't sure at that time, though I may have been wrong," he later wrote, "that a Jew at the head of the new party would be best for the movement."

In 1989, Audrey McLaughlin became the first woman to lead a major federal political party when she took over the NDP.

But the party also has a history of losing elections which, in the end, could prove to be a bigger obstacle for Singh.

Numerous studies have found that partisanship is a more powerful force than racial bias in influencing how voters cast their ballots.

What is deemed acceptable can also shift dramatically, depending on partisanship. Americans in general became more tolerant of immorality with the nomination of Donald Trump as the Republican presidential candidate last year, but no group experienced more growth in that tolerance than U.S. evangelicals, a voting bloc that is heavily Republican.

The poll conducted by ARI in June found that 37 per cent of Canadians thought it was probable that a Sikh would become prime minister within 25 years. Their more recent sounding, however, found that just 28 per cent of Canadians polled believed the NDP would form government within the next three elections.

Polls also show fewer Canadians would consider voting for the NDP than for the Liberals or Conservatives.

So not only does Singh need to convince Canadians they are ready for a Sikh to be prime minister. History shows how that can take a long time — and that the right leader can be transformative.

He'll need to make Canadians believe that a New Democrat is right for the job, too.