Preposition: of

• supporter: In 1967 however, the club folded and was it only through the determination of a hard core of supporters ( sound familiar?

• user: Whilst Longparish welcomes visitors, the hard core of users needs to come from the village to secure the sustainability of these facilities.

Converse of object

• remain: There does remain a hard core, however, which is probably really only a single entity masquerading.