You do not ask if there is an inside candidate.
I don’t care if you strongly suspect that there is, and have good reason to believe the whole damned search is a completely pointless charade because they obviously already have somebody chosen….it doesn’t matter.
You cannot, and you must not, ask if there is an inside candidate.
Why? Because it’s just Not. Done.
More pragmatically, if there is an inside candidate they will NEVER disclose that (not least because of legality issues). And if there isn’t one, you just look like an ill-informed, paranoid ass who put a search committee member in an unbearably awkward position.
A smart job seeker does not, under any circumstances, ask if there is an inside candidate.
And, incidentally, inside candidates don’t have the superpowers that many of you think. Inside candidates frequently don’t get the job. Read this post, “What Inside Candidates Persist In Doing Wrong,” on why.