Oh? A whitespace argument? I love whitespace arguments! I have a standard set of tactics! I say that I defy you to make an argument for spaces that isn't:

1) An argument of authority
2) Cyclical
3) Just an argument for choosing one or the other and sticking with it.

I'll start with my own argument for tabs: Beginning-of-line tabs used as "indentation levels" allow each person to set their editor to display source files with their desired indentation settings without ever messing anything up.