>I wonder how that site ever got the www.whitehouse.org domain name?

Probably it was simply available. That's the problem of having several TLDs (top-level domains). If you don't grab the same name in all of them, it is likely that someone else will.

For example, the same name (whitehouse) with:

.gov - is the official White House site

.com - is a pornography site

.org - is a parody site

I understand pornography sites often use likely misspellings, too, to attract unsuspecting viewers.

Difference in opinions hath cost many millions of lives: for instance, whether flesh be bread, or bread be flesh; whether whistling be a vice or a virtue; whether it be better to kiss a post, or throw it into the fire... (from Gulliver's Travels)