His remarks got that credibility because of the rush and secrecy used to bail out the institutions last year. Kanjorski isn't the only legislator that was told "the economy will crash if you don't pass this RIGHT NOW!" Like the urgency to invade Iraq in 2003, there won't be any direct quotes by administration people claiming "DOOM!" while at the same time, every utterance, every speech, and every interview was carefully crafted to give the message of "DOOM!"
And since the stories of why such drastic measures had to be taken immediately made little to no sense to the public, people had to fill in the gaps with pieces of stories that indeed made sense to them.
Perhaps because he's on the Financial Services Committee and Capital Markets Subcommittee and gets personally briefed by Paulson. That's a lot closer to the source than a Portfolio.com blogger.
It immediately seemed false to me. Still, my initial suspicion was that he was being lied to by Paulson's crew, not that he was cribbing unsourced figures from the NY Post.