Conditional Transformition for CDATA node

Can you write a match for an element containing CDATA?  The thought
is:  raw web content in a CDATA element, and some web content will be
well formed.  So I might have something like:

<root>
  <data>
    <div>foo bar<br/>foo bar</div><!-- well formed -->
  </data>
  <data><![DATA[
    <p>not so foo<br>barf<!-- not well formed -->
    ]>
  </data>
</root>

In one case, I'd simply xsl:value-of the data element, and in the
other case, I'd write an identity transformation for it.

Thanks,
Karl..