Mr. mcdonough has just been discussing the idea that being "less bad" is not the same thing as being good. he uses the analogy about driving to canada or mexico for what purpose?

Mr. McDonough used the idea and the analogy for purposes of defining that Path means more than speed.

Explanation:

First of all this analogy have the objective of differentiation between being good and less bad. Because while one road can be easier to take to achieve and objective it doesn't really means it is good. So, he wants to say that being good is a very different path from being less bad. That it is a certain different one and that someone could be mistaken about identifying one from the other from an attractive trigger, but in the end, it keeps being bad. So, he uses this analogy to board the topic in two different ways. So that the person who is listening to him can take 2 approaches.