Polling is a science that can accurately measure almost anything at a given moment , should those commissioning the poll want public opinion and not want to mold public opinion..
Marketing and polling are used hand in hand as a tool of advertising to get you to think what they want you to think.
Whether it is Mountain bikes, tooth paste , or the president.
As to the merits of polling..It works..Either in finding a market for a product setting up an ad campaign to get you to do something..Polls are scientific and it unfortunately leads one to believe that too many people are like sheep.
There is a reason , next to my 'share the road' bumper sticker is a sticker saying "Kill Your TV."