Does "Genocide" Have Any Meaning Left?

I am happy to hear that former Mexican president Luis Echeverria has been charged for his crime of ordering the 1968 Tlateloco Massacre. That was perhaps the low-point in post-revolutionary Mexican history and certainly marked the end of anyone considering the PRI a progressive force in Mexican society.

But the crime he was charged with is genocide. What? How can this possibly be considered genocide? Genocide is the destruction of an entire ethnic, racial, or political group. Tlateloco was awful and certainly was meant to decimate radical Mexican students, but it was not a coordinated attempt to eliminate all activists or students from Mexican society.

This bothers me so much because by calling acts such as Tlateloco genocide, it obscures the real meaning of the term when it needs to be used. Hitler and the Jews, Rwanda in the 1990s--this was genocide. A single massacre of leftists? Definitely not genocide.