Get TEXT value of a CLOB OID in Postgresql
Thanks goes to a_horse_with_no_name.  Solution is:

update answers set answer_value = lo_get(cast(value as bigint))


Note - the lo_get function appears to be present in Postgres 9.4 or higher.  For earlier versions, I don't see a way of doing this directly.  I'm currently running 9.0, but this just accelerated my upgrade plans.