"Texas Drinking Rules" joke

A Mexican drinks his beer and suddenly throws his glass in the air,
pulls out his pistol and shoots the glass to pieces. He says, "In Mexico our
glasses are so cheap we don't need to drink from the same glass twice."
An Arab, obviously impressed by this, drinks his beer, throws his glass into
the air, pulls out his AK-47 and shoots the glass to pieces. He says, "In my
part of the world we have so much sand to make glasses that we don't need to
drink out of the same glass twice either."
The Texas cowboy, cool as a cucumber, picks up his beer and drinks it,
throws his glass into the air, pulls out his pistol and shoots the Mexican
and the Arab, and catches his glass. He says, "In America we have so many
illegal Mexicans and Arabs that we don't have to drink with the same ones
twice."