Is this idea possible? For a more expansive crisis in American-Mexican affairs over German support of Mexico with the government of Mexico being in general more cooperative with the Germans than it was OTL? What sort of things would be needed to facilitate this? A worse Mexican Revolution (which in a way was a rather large undeclared war between Mexico and the US, since the US basically occupied portions of Mexico even after Huerta told Wilson to get the hell out)?
I would imagine this would largely be a rather speedy conflict, Wilson wouldn't want to waste time in Mexico on the way to a larger war with its biggest supporter, Germany. I can see public sentiment rallying even more against Germany than OTL, which could either result in a USA that's more amenable to harsher provisions of Versailles or (with adequate political exploitation of the situation) more amenable to Wilson's calls for a peace that prevents further conflict. I could really seeing it go either way depending on A. the skill of Wilson and his goals and B. how the political situation in general turns out to be.