Why should I hire you from the outside when I could promote someone from within?

Help him see the qualifications that only you can offer.Example: “In general, I think it’s a good policy to hire from within – to look outside probably means you’re not completely comfortable choosing someone from inside.

“Naturally, you want this department to be as strong as it possibly can be, so you want the strongest candidate. I feel that I can fill that bill because…(then recap your strongest qualifications that match up with his greatest needs).”