SQL & PL/SQL :: Inserting Multiple Records With CLOB Using Select

I'm updating a large piece of legacy code that does the following type of insert:

INSERT INTO foo_temp
(id, varchar2_column)
SELECT id, varchar2_column
FROM foo;

We're changing varchar2_column to clob_column to accommodate text entries > 4000 characters. So I want to change the insert statement to something like:

INSERT INTO foo_temp
(id, clob_column)
SELECT id, clob_column
FROM foo;

This doesn't work, since clob_column stores the location of each text entry, rather than the actual content. But is there some way that I can achieve the insert with one call to a select statement, or do I need to select each individual record in foo, open the clob_column value, read it into a local variable and then write the content to the matching record in foo_temp?