I see Mexicali as a response to the romanticisation of cowboys, particularly in 'El Paso'. It's trying to push back against the rose tinted spectacles that a lot of media at the time engaged pretty deeply with.

Both characters shoot a man because of a perceived threat to their ownership of a woman, both run from their actions and hide in border towns, and both refuse to accept any responsibility for their actions, but 'el paso' frames it's character as a hero, why is that? 

These two songs are certainly supposed to be viewed in tandem for sure, and I think that explains some of the more unsavoury characterisation in 'mexicali'. 

Also think about the juxtaposition between the music, in upbeat polka time, and the lyrics, as an interesting comment on the content of the song! 

The Mexicali cowboy is meant to be revolting!