The fact is _that this policy will never win_.
The clause, _that this policy will never win_, is here used in the
predicate with the copulative verb _is_.
4. +The noun clause may also be used in apposition, explaining the noun
with which it is used+, thus:
The motion, _that the question should be reconsidered_, was carried.
_That the question should be reconsidered_, is here a noun clause, used
in apposition with the noun _motion_, and explains the meaning of the
noun.
5. +The noun clause may also be used as the object of a preposition+,
thus: