I found this reference to a Member of Parliament in two of JA's letters, dated October of 1813. This would be after S&S was published, but perhaps it shows Jane's or her family's opinions of what M.P's were generally like:

Mr. Lushington (M.P. for Canterbury) goes to-morrow.

Now I must speak of him, and I like him very much. I am sure he is clever, and a man of taste. He got a volume of Milton last night, and spoke of it with warmth. He is quite an M.P., very smiling, with an exceeding good address and readiness of language. I am rather in love with him. I dare say he is ambitious and insincere.

Could anything be less like Mr. Palmer--very smiling, exceeding good address, etc.? Her family must really have laughed at the idea of such a person becoming an M.P.! "Mr. Palmer is always going about the country canvassing against the election; and so many people come to dine with us that I never saw before, it is quite charming! But, poor fellow! it is very fatiguing to him! for he is forced to make everybody like him."