oversaw border fencing as expensive as it was


Senior Member
" When you were heading INS, you oversaw the installation of border fencing, as expensive as it was. What convinced you that that would be a good use of resources? Let's talk about the merits of more fencing."

I can't make of how "oversee" and "as expensive as it was" are connected. The verb oversee doesn't seem to be used with "as as" construction.

source: Migration Policy Institute Senior Fellow Fact-Checks Trump's Border Wall Claims