I think you could ask an LLM if they were persuaded, but I don't think you'd get meaningful data from it

Leaving aside the bots that are trained to answer "as an LLM I do not have opinions..." it's going to be a very basic probabilistic yes or no based on tone and numbers of pros and cons rather than knowledge of the surrounding political context and higher order reasoning about the accuracy of the claimed pros and cons.

Yeah the bot has both no initial position and no internal opinion on fact that an argument could operate on. It might write you a cogent response but it's fundamentally not a question an LLM can meaningfully answer.

Relevant useful dataset: https://paperswithcode.com/dataset/debatesum

I like this question. I've always wanted to be able to compute, somehow, the "partial derivative of x with respect to y," where x is a proposition and y is an argument or a piece of evidence. It seems to me as though we're closer than ever before. The models are still fairly opaque, but I'm hoping the interpretability research will succeed and allow such introspection!

If you tell the LLM it is conservative it will report it was persuaded by the conservative speaker, if you tell it it is a liberal it will say it's persuaded by the liberal speaker. It will be happy to roleplay at being persuaded but I don't know why that would be useful?