Do (or should) public opinion make any difference?

Another Issue Where Barack Obama and I Agree — Repealing the Mortgage Interest Deduction

Just a side note to the discussion by Ilya Somin:

...the fact that Obama had more political clout then than he does now, when his popularity has dropped.

Do opinion polls really make a difference? Well maybe with Democrats, yes. Otherwise, Republicans like Bush seem to blithely ignore public opinion --- which as it should be -- if they can get the votes. Obviously there is a matter of scale and judgment. And the voters are not infallible on a day-to-day basis. So a smart elected official should listen but sometimes ignore what the public may or may not actually believe.