Obama backs off NAFTA attack ahead of McCain visit to Canada

Obama, who said in March he would renegotiate the North American Free Trade Agreement if he's elected, said he might have gone too far. "Sometimes during campaigns the rhetoric gets overheated and amplified," the Democratic nominee told Fortune magazine in an interview.

Were his attacks on NAFTA a product of that brand of campaign posturing?

"Politicians are always guilty of that, and I don't exempt myself," he answered.

The admission was published shortly before McCain was expected to pour unvarnished praise on NAFTA, drawing a clear distinction between America's two combatants for the White House.

The debate over trade puts Canada in an unusual position: right in the middle of a campaign for the U.S. presidency.

A spokeswoman for Prime Minister Stephen Harper confirmed that he and Obama had a conversation recently, but would not provide details of the call beyond saying that Harper congratulated the Illinois senator after he became the presumptive Democratic nominee for president.

Sandra Buckler said Harper made a similar call to McCain a few months ago.

North American free trade and Canada played a pivotal role in at least one battleground state - Ohio - during the U.S. primaries.

A Canadian government memo written after a meeting with an Obama adviser suggested the Democrat's biting opposition to the pact was rooted in politics that would not blossom into policy if Obama becomes president.

That memo was leak to The Associated Press and many of Obama's own supporters believe it cost him the Ohio primary, which was won by Hillary Clinton.

Harper condemned the leak in the House of Commons as "completely unacceptable" and ordered an investigation into the matter.

An internal inquiry put the onus on the memo being too widely circulated among bureaucrats. The exact source of the leak remains a mystery.

A spokesman for McCain says the Republican is jumping off the U.S. presidential campaign trail and travelling to Canada to speak his mind on free trade and not to win votes.

McCain will meet with Foreign Affairs Minister David Emerson and Gen. Rick Hillier, the chief of defence staff, in an effort to "demonstrate his view on the importance of the U.S.-Canadian relationship," said Republican policy advisor Randy Scheunemann.

Scheunemann, director of foreign policy and national security for McCain's campaign, said this is "not a campaign trip" and jokes there are not many American votes to be had in Canada.

McCain will address the Economic Club of Canada in a sold-out luncheon speech.

"(The speech) will be about the whole breadth and depth of the relationship, economic and, of course, that includes free-trade, but as well as other issues such as environment and security and so on," says Scheunemann.

The Harper government has been careful not to appear to have favourites in the American presidential race. Democratic strategists, such as party elder Bob Shrum, have accused the government of manoeuvering to help the Republicans by leaking the NAFTA memo.

McCain has touted the value of NAFTA since the start of his campaign, repeatedly saying the agreement is not up for negotiation if he becomes the U.S. leader.

The senator's visit to Ottawa has been met with criticism from those who say the trip puts Canada in the middle of the U.S. election, despite repeated comments from McCain's camp that this is not about the election.

Liberal foreign affairs critic Bob Rae says that's a hard line to swallow considering the timing.

"A visit in the middle of an American election is a campaign trip and to suggest otherwise is being disingenuous."

McCain's strict views on free-trade have been one of the senator's central platform issues, but Rae says it looks like Canada is being used as a soapbox to further market McCain's message.

"It's a little unusual to be giving a partisan speech to a Canadian audience . . . . The speech is not intended for us it's intended for a prime-time American audience," says Rae.

"It looks as if we are being used as a bit of a prop."