If a national favorability poll were to be taken concerning a state representative, would the poll be accurate, or even relevant?

have no idea

That depends on the question and sample.

I mean, if you do a national poll concerning A state representative ... it wouldn't be relevant to how the people of that district feel

On the other hand, if you do a national poll concerning state representatives in general ... it would be more relevant.  But still less relevant than a district poll of the representative for that district.

And a larger sample size would be more relevant than a smaller one. This post was edited by Walt O'Reagun at November 13, 2018 5:52 PM MST

The problem with any poll is that the pollster has complete control of the questions and determining the results. 

Do you feel person x is doing a good job? Yes or no?

hard to answer. x may be doing some things well and others not at all. 

But you you can only answer yes or no. 

have no idea