No Takebacks!!

Of all the things that have arisen about the mysterious Obamacare bill, this one seems, to me, to be the one that should get trumpeted from the rooftops. How is this Constitutional??

Buried in the amendment is a bombshell; there will be no way to amend parts of Obamacare. Apparently, Reid wants to make this bill something like a royal decree where no one can change what has already been wrought.
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Get that? No repeal, no amendments, no nothing. That part of Obamacare is as set in stone as the idea that the sun rises in the east and sets in the west. It is unalterable - which, of course, means the entire bill is off limits

Now, if I understand the issue (and it's entirely possible that I don't), the problem is that since an amendment in the bill changes Senate rules (which normally require a 2/3 vote), the entire bill should also require a 2/3 vote, rather than the 3/5 (60 votes) which it normally would require (and which it got). Anybody know for sure?