On the recordJanuary 29, 2008
If we did not have a 60-vote requirement on amendments, or dealing with any issue in this bill, then it is possible that we could adopt amendments, by less than a majority of the Members of the Senate, which could hamper our intelligence community. And on this critical, sensitive, most important piece of legislation, for us to pass an amendment without a 60-vote requirement really makes no sense at all. I think all of us would certainly be remiss and derelict in our duties if we didn't insist on a 60-vote requirement.
Source
govinfo.gov




