why do we think they're right?

i've never understood the purpose of opinion polls.
i read an article this morning that says Bush's ratings have "fallen in the polls again"
who cares?
i don't understand why people think public opinion is right. it's opinion. opinion is the operative word there. but the media presents it as fact, and we accept it as fact. public opinion says x is bad, so it must be bad. why do we assume that?

let's be honest, how many members of the general public know enough about the presidential office, or how our government works, to have even an accurate opinion? what do most people base their opinion on? stuff they hear on the news? right.. 'cause that's a reliable source. most opinions are just someone else's opinion regurgitated. at least, that's what i've found.
everyone's upset about the war in iraq. but how much do they know about it? how much of their own reading and research have they done? have they heard or read stories from people who lived under Saddam's dictatorship? have they heard the stories of torture? execution? families fleeing the country for their own safety? have they investigated enough to find out that iraq has no basic infrastructure? no electric companies, no water treatment plants, barely any running water, no waste disposal. they live without the basic, foundational things we take for granted, and then we wonder why it's taking so long to help them get established.
people complain that we should be "taking care of our own", and yet the poorest of americans have more than the majority of the iraqi population.

i just finished reading a book written by missionaries in iraq. they told a story of the day saddam was captured. they said it was the first time the country seemed truly united. religious and political differences, for just a day, didn't matter anymore because people were celebrating saddam's capture. celebrating the idea that maybe they really could be free after all.
this wasn't meant to be a diatribe about iraq. just about opinion polls. but i guess people's opinion of the iraqi war is one that i don't understand so i naturally go there for my example.

anyhow... public opinion polls.... i just don't get the point.