> I can't copy www.whitehouse.gov. Does anyone know if
> this is possible with HTTrack

Don't tell us what you're not getting, what version, what settings, or what
the log says; so only mind readers know.

You may need to override robots.txt since it says:
User-agent: * 
Disallow: /includes/
Disallow: /search/
Disallow: /omb/search/