I sometimes find peoples ideas about trademark law to be silly. The original point of trademark law was a form of consumer protection so that there would be less confusion in the marketplace, and that a mark used in trade could inform consumers about the origins and history of the producer.
I see no way there could be confusion in the "marketplace" between The Green Shift political campaign from the Liberal party of Canada, and the Green Shift company in Toronto, and yet according to a Globe and Mail article the owner of the company is threatening to sue.
I believe it is Ms. Wright's trademark search (Note: no granting of trademark) and then through the media an attempt to enforce a non-existent trademark on something as common as the phrase "Green Shift" which is "so blatantly unethical”. I do hope that the Liberal party defends themselves against this behaviour, and helps to clarify for people getting this issue wrong what a trademark really is, and what it is for.