Dean is from a Congregationalist background, a liberal denomination that does not believe in ministerial authority or church hierarchy. Each Congregationalist believes he is in direct contact with God and is entitled to sort out truth for himself.
I have no problem with the Dean bashing (particularly in light of the comments posted on this article), nor do I doubt that he belongs to a liberal "church". Nonetheless, you should be a bit less generous with the 'broad-brush'.
Congregationalists, along with Presbyterians and Episcopelians (of a former - more conservative time) were the predominant denominations of the God fearing men and women that founded this country. There is nothing that equates Congregationalists with liberalism. In fact I'd argue you'll find less faithfulness to the Bible amongst the larger, more centralized denominations, than you will amongst the smaller independents.
Regarding church 'hierarchy' - there is much in the Bible regarding the authority within an individual church (set through elders and deacons), but beyond the setting within an individual church - the rest is largely man-made (there is one passage in Acts regarding the controversy of circumcism that was brought to Jerusalem to be presented to the Apostles, with James as their leader, for discussion --- but its a stretch to build this as a case to justify an intra-church hierarchy).
And finally with respect to your comment that: "Each Congregationalist believes he is in direct contact with God and is entitled to sort out truth for himself". I would hope that all believers have, and cherish, a personal relationship with Jesus Christ - God the Son - our Lord, High Priest, and Saviour...And don't rely on another as their mediator.
Those words were not mine, but were from a quote, which I had highlighted the part that I wanted to emphasize. I should have put the whole quote in Italics. Sorry, for the misunderstanding.