Armed with stickers, pamphlets and other canvassing paraphernalia, they pounded the sidewalks, bounded up and down stairs, knocked at doors, and chatted about voting day with residents and passers-by.
"From Canada? Wow. That's amazing," said Linda Herring as she stood on her porch.
"I love it because Obama's the man," Stanley Ryant said of the foreign volunteers, a faded Stars and Stripes fluttering in the wind in front of the home. "It's well appreciated."
A few in the group of a dozen Canadian volunteers — most well-heeled lawyers from Toronto — campaigned for Obama in 2008 in a gritty 'hood in Pittsburgh, inspired by the Democratic candidate's message of hope and promise.
Four battering years later, with Obama's re-election less assured, they feel it even more important to do what they can in their own small way to keep his Republican rival, Mitt Romney, out of the White House.
Mitt Romney's principles seem to change day-to-day, depending on what he thinks he needs to gain public support, says Ian Roland, a Toronto lawyer.
"He doesn't seem to be someone who is seeking the highest office in the United States out of some particular principles, but simply because he wants to be president."
Clearly, the group is not alone among their countrymen in supporting the president. A recent GlobeScan poll for the BBC found 66 per cent of Canadians want Obama re-elected. Just nine per cent picked Romney.
Exactly how many Canadians are in the U.S. working for either campaign is difficult to come by.
But at the West Philly Obama campaign office on 52nd and Walnut, the enthusiastic co-ordinator says he has had more outside than local volunteers, the Canadians among them.
"It's fantastic," says Clyde Sherman, breaking out into convincing rendition of "O Canada" picked up from watching baseball and Olympic TV coverage.
"Our government has such an effect on the whole world economy, it may be the future that other countries have an opinion on who's going to be the leader of the free world."
West Philly, with its uneven sidewalks and at times derelict properties, is just a few kilometres from the high-priced hotels and restaurants around such iconic places as Independence Hall — the birthplace of the U.S. — and the famed cracked Liberty Bell.
While Pennsylvania's unemployment rate — at 8.1 per cent — is slightly less than the national average, it's about double that in West Philly.
In this 'hood, there are no genteel horses and carts carrying tourists. But it is emphatically Obama territory.
Many door knocks go unanswered. One woman lets out a quick frightened scream when she opens her door, before warming to the interlopers. Many residents insist on talking through the screens or just a crack.
Overall, however, there's little opposition to the message, and they all take the campaign literature or listen to exhortations to vote.
"I'm going to be supporting Obama. Positively. Who else if it is not Obama?" says Dartina Flahn, surprised by the question of whether the president can count on her support Tuesday.
At one door, however, a woman makes a point of saying she won't be voting for America's only black president.
"I'm a Christian," she says by way of explanation, before denouncing Obama's pro-choice views and support for same-sex marriage.
But just around the corner, Rev. Dennis Earl Thomas is thundering a different message to his congregation at the First Corinthian Baptist Church.
"I cannot tell you who to vote for," he says, before launching into a lengthy pro-Obama, anti-Romney oration.
"I want somebody in the White House who reads the Bible, not the Book of Mormon," says Thomas — taking a jibe at Romney's Mormon faith.
Congregants — one woman has tears streaming down her face — respond knowingly and appreciatively.
Pennsylvania has voted Democrat in the last five presidential elections, and opinion polls suggest this one will be no different, despite a surprise push from Romney, who made his first campaign visit to the state on Sunday. Former U.S. president Bill Clinton, urging an Obama win, was making four campaign stops in the state — including one in West Philly on Monday.
Given the strong Obama support, the key issue for the volunteers is making sure residents vote. Most know where their polling station is — the local YMCA — but some are confused about what ID they need. A Pennsylvania court ruled recently photo ID was not required but could be asked for.
The volunteers, both in the lead-up to the vote and on election day itself, are involved in voter protection: ensuring those who are eligible to cast a ballot can do so if they wish.
"We've tried to clarify that for them," says Brian Gover, another Toronto lawyer.
"There are some people now who are going to turn out because of the effort we've expended."
Some in the group concede not all Canadians would be as hospitable to Americans crossing into Canada to campaign for an election candidate. At the same time, the volunteers say what they're doing is simply part of a larger democratic process.
"In a democracy, others are going to have an interest in what we do just like we have an interest in what they do," Gover says.
"This is, in part, what we do as citizens of the world."
In West Philly at least, where jobs are hard to come by and white faces are few and far between, many residents find the Canadian volunteers' efforts inspirational.
"That makes me want to vote even more," says Nigell Rivers.
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