In chapter 6 of Animal Farm, what is Squealer's role for Napoleon?

Throughout the novel, Squealer's primary purpose is to
make sure that the animals fully support Napoleon's policies and the reign of the pigs. 
As life for the animals becomes more difficult and challenging, Squealer's role and need
increase because there is a greater need to "spin" what is happening on the farm.  For
example, Squealer explains the difficulties of increased labor on the farm and greater
difficulty as a result of Snowball's treachery and his disloyalty.  In this, one sees
Squealer's great ability to both increase the legitimacy of the pigs' rule and alienate
their enemies, at the same time.  Squealer's purpose is being able to ensure that public
loyalty is present with the pigs' administration on the farm.  His ability to craft what
is happening and "spin it" to the animals is what allows the pigs to continue their
rule, uninterrupted, despite the challenges that the animals endure.  Napoleon finds
Squealer invaluable and more needed as difficulties on the farm mount.  He understands
clearly that one of the reasons why the initial revolution was successful was because
Mr. Jones never really communicated with the animals.  Napoleon wishes to avert this
fate, and in this, Squealer proves to be essential for Napoleon and the pigs to remain
in power.