Because the House is elected from smaller, less diverse constituencies, has cheaper election campaigns, and has 435 members, it just seems natural that it's always going to have a few nutjobs in it. It's not like they wield much influence over Congress: in fact, in the era of the soundbite, their chief function seems to be as inadvertent fundraisers for the opposing party. Which is exactly the reason for the manufactured panic described in the article.