Oh say what is truth?

The CBO, congressional budget office has long been valued for it's nonpartisan analyses of various government proposals.  But recently Speaker of the House John Boehner dismissed their standing with a flippant "the CBO has a right to their opinion".  It isn't their opinion that makes the CBO a valuable resource.

A local Sacramento opinion shaper and father of an autistic child refuted a recent science news article by saying, in essence, we know that our child's autism was caused by vaccines no matter what research shows otherwise.  In other words, my mind's made up, don't bother me with the facts.

In both these examples we see people confusing fact with opinion.  In the preface to Thomas Sowell's "Economic Facts and Fallacies" we read "Some things are believed because they are demonstrably true.  but many other things are believed because they are consistent with a widely held vision of the world -- and this vision is accepted as a substitute for facts.

Is science equal  to truth?  When is science equal  to truth?  Why do respected leaders talk about scientific results as if they were just another "opinion" to be debated in the world of opinions?