I read everything that mentions amendments, and it appears that they either must come out of committees, or be sponsored by a single senator. It looks like the Clerk would know who sponsored an amendment. Though, I'm not sure how this plays in, but at least one of the rules specifically says, "This rule does not apply to the President Pro Tempore, the Majority Floor Leader, the Minority Leader, or the Assistant Minority Leader of the Senate," in regards to limits on number of amendments to a bill.
My guess is that it's not "anonymous" in the sense that no-one knows who added it, but that it's not "transparent", i.e. came out of a committee or was put in by one of the leaders (above) in the Senate.
I'm sure they know who added it, the question is do they have to tell anyone (they should have to for government transparency).
PS Intimating is the wrong word. I think you meant infer instead of imply.
Probably.
>PS Intimating is the wrong word. I think you meant infer instead of imply.
...no, I don't think they did? They denied implying anything about Ohio.
Incidentally, it seems like the usage of both imply and intimate in this way comes from about the same time, ~1580s.