John Kerry, aka Kaptain Ketchup, tries to tell people what he thinks they want to hear. That means he will change his story from group to group, even contradicting himself in the process.
It does seem difficult to contradict yourself, and then insist that your position is always consistent.
My opinion is Kerry is a damned liar, who even believes his own lies.
It's typical for members of Congress to reserve the right to "revise and extend my remarks" at the beginning of a long bloviation. This is what explains the difference between some incoherent babbling of Ted Kennedy on the floor of the Senate and the coherent but misguided crap that appears in the Congressional Record a few days later. It's the handiwork of his staff making editorial revisions that can be major changes from what was actually said. This is one of the reasons that Justice Scalia has said that reading the legislative history of late is a pointless exercise when trying to interpret a statute. When the statements made immediately before the vote can be one thing, then appear in the Congressional Record as quite another several days later, well...
I'd like to see video of Kerry's speech and then compare it to the transcript.
Acutally, Kerry reminds me more of Bullwinkle's ally Captain Peter Peachfuzz.