Why can't the secret vote be taken in a much more timely manor?
Without getting into a presentation of a dissertation, let me just say
that in the last eight years the Bush Admin has stacked the deck against
unions in terms of union elections, decerts, allowing employer
intimidation, employer delays and packing the NLRB courts. Some of that
will change with the new administration, and if it does, and the playing
field is fairer, there will be less call for card certifications.
In recent years, a favorite tactic of employers has been to refuse to
negotiate in good faith, even after a union has won a rep election.
If you are interested in the subject, there's a decent synopsis here under
union busting: