Canada, like the US, wasn't letting unvaccinated people cross the borders. What
@RangerRay was saying is there is no timeline where the US would have listened to Canada telling them to let in unvaccinated Canadians because we thing they should, regardless of what our stance was on the vaccination requirements for Americans entering Canada.
The US regularly stops Canadians and others from all over the world going across their borders for any number of reasons, kind of how national sovereignty works.
A lot of the protesters were pissed off because the US wouldn't let them in without a vaccination, and somehow blaming the Federal government for the decision of a sovereign country and blaming Trudeau for not telling US border guards what to do. The lack of basic understanding of civics was kind of shocking, and hearing people talking about their US constitutional rights as a Canadian in Canada was both funny and sad.