Postgres casting issues with 'deleted' column updates

I'm getting a variety of casting issues when running smoke tests with Postgres. Several calls in the DB api throw exceptions like:

LINE 1: ...='2011-06-06T18:26:33.641652'::timestamp, deleted=1 WHERE ke...
                                                             ^
HINT: You will need to rewrite or cast the expression.
 'UPDATE key_pairs SET updated_at=updated_at, deleted_at=%(deleted_at)s, deleted=%(deleted)s WHERE key_pairs.user_id = %(user_id_1)s' {'deleted': 1, 'user_id_1': 'test806927user', 'deleted_at': datetime.datetime(2011, 6, 6, 18, 26, 33, 641652)}

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We need to update several of the DB API calls so that they use True/False instead of 0/1 when updating the 'deleted' column attributes.