The Globe and Mail reports in its Tuesday edition that Stephen Harper's memo, "Napping on NAFTA," has put a crack in Canada's united front in the North American free-trade agreement renegotiations. The Globe's Campbell Clark writes that Mr. Harper's memo will encourage Conservatives to start slipping off the Liberals' NAFTA message. The Conservatives have been playing ball with the Trudeau Liberals' call for a beyond-partisan approach. The Liberals had reached out to ask former prime minister Brian Mulroney to help, and asked former interim Conservative leader Rona Ambrose to serve on a NAFTA advisory council. There are signs, however, that Conservatives itch to be free of those chummy constraints. The biggest part of Mr. Harper's memo was warning that talks are going badly, and Mr. Trump might pull the plug. Canada, he said, must realize that it does not matter if it gets a worse deal than what it has now; what matters, "is whether it is worth having a trade agreement with the Americans or not." That is partly a reflection of the sour feeling that the talks could fail. That prospect also encourages the opposition to break more with the government's handling of the negotiations.