As Alfred Mangion notes in his letter (May 1) we "have always been told that the cardinal-electors, when convened in conclave to elect a Pope, pray to and are guided by the Holy Spirit when making their choice" and even invoke the Holy Spirit by singing the Veni Creator.
However, in his homily given during the pre-conclave Mass, the (then) Cardinal, now Pope Benedict XVI, Ratzinger in effect, urged his fellow cardinals to ignore any liberal inspiration they might receive. It was thus a party-political broadcast on behalf of the conservative wing of the Church, of which he was effectively the leader. In delivering his homily, the cardinal presumably intended to sway the final result and so would appear to have usurped the role of the Holy Spirit.
This surely reveals an underlying anxiety on his part as to the adequacy or potency of the divine inspiration the cardinals were about to receive and could indicate an uneasiness as to the validity of the entire electoral process.