rightRasmussen was also hard on BushRasmussen always leans against him. Notice they're the only poll with a negative spread?
And it's much more likely that the third option is "mixed views", not "I don't know".
because they dont have a third option other than approve/disapprove
Exactly. Actually, Rasmussen uses 4 choices - strongly approve, approve, disapprove, and strongly disapprove.
but there is no neutral option