Respuesta :
Politicians would be hesitant to do this because over time, that data may change. If they have gone on record as saying that they are for or against something specific, then it could be used as an argument against them.
Answer and Explanation
This is because the know that these research data s may sometimes change due to some unpredictable issues which may favor or go against the data survey which was presented.
If they base their speeches on these research records they may encounter arguments from different peoples who are the people they are serving and most probably their op-posers and competitors. Then it could be used as an argument against them. So to be on save side they normally base their speeches on things which they know they have potential to do and which cannot change with time. And if they are to change they change on positive effects.