Any time you're dealing with a U.S. congressman or senator, the more you can take advantage of opportunities to have American friends with you in those conversations, or at some point during that visit, the more powerful it will be--just as in your ridings you're going to care a lot more about a company, business person, chamber of commerce, or citizen from your riding than someone from the U.S. telling you how important the U.S. is to Canada. The opposite is just as true, and in fact even more so given how vast the U.S. is. The vast majority of U.S. congressmen and senators aren't anywhere near the northern border, so they have never had any real reason to deal with that subject, learn about it, or really care much about it.
I cannot overstate the extreme lack of awareness among members of Congress and senators--and even more so at the staff level with those who are driving the writing of papers, position papers, press releases, schedules, etc.--about how important Canada is to the economy of every American. And that's not just Americans who live in Michigan or New York, but Americans who live in Iowa, Kentucky, and Florida. Much more needs to be done for all of our sakes to get that message across, but it needs to be done in partnership with Americans in order to be effective.
So it's not the nice courtesy sort of thing of receiving some colleagues from another country, having a conversation, and being undoubtedly very well-meaning about that conversation. When that meeting is over, it's not going to stay on the agenda as something very important to them when their own constituents pull them back in other directions.