To identify a troll sounds more art than science.
It does seem to me, however, that a conservative web site would be justified in stating that liberal ideas, in general, had been rejected and are not part of the desired debate. It seems fair to send advocates of these ideas on to sites that welcome them. It seems fair to confine the debate within certain parameters desired by the founder of the site.
Isn't a "troll" anyone with whom a poster disagrees?
Does that mean that things like support by conservatives for nation building is a given truth and those who deviate from the acceptance of that shouldn't talk about that subject?