Beyond AMLO's obvious self interest - he is, after all, running as a candidate in 2012 - I fully agree with his point: Spoiling the battle will not do the least service to Mexico's progressive forces, quite the contrary, just like the foolish 2009 "voto nulo" campaign achieved absolutely nothing but effectively handing over more votes to the PRI.
Sicilia is in every right to spoil his ballot, and call upon others to do the same.
We are also all in our right to denounce this as reckless stupidity.