Latin America as a whole is crazy about football, and it is not just Mexico. In case of Mexico, they are located close to the United States and therefore they were included in the combined bid to host FIFA 2026. The situation is entirely different in the United States and Canada. In the US, baseball (MLB), American football (NFL), basketball (NBA) and ice-hockey (NHL) are far more popular when compared to soccer. The same can be said in Canada as well, where NHL is the most popular league. But during the recent years, MLS has gained popularity (especially among the new immigrants).
We know the Latin countries are crazy about football in their country but this time the world cup will be hosted in America and all the teams hosting the tournament will be from America. In my opinion, Mexico is more popular with football fans than the United States and Canada. As you have mentioned, football is not the first favorite sport in north America, so I hope the Mexican people and Mexican fans are more interested in football than their northern counterparts.
No doubt, Mexico got influenced by some things in the South America which includes football and I'm already expecting that they will reach further than the other 2 countries that will also host the WC namely, Canada and USA.
While for America, their most loved and most watched sports is basketball and baseball, and then rugby comes in 3rd (which is football in America while soccer was named rather than football). Same as Canada, they too got their own sports like ice hockey which comes in 1st.