Evidence itself cannot actually lose it's credibility if it is empirically proven to be fact.
However, in today's world what is presented as evidence is far from truth, both in politics and religion.
We have turned into a society of liars, haters, and doubters.
Common sense, logic, or even critical thinking, are no longer options for the sane.
A great example of the stupidity of people in general is when you see/hear the results of "polls" as proof of anything. That is the biggest joke of all. Even "polls" are tainted by virtue of being taken in the groups that one knows to be in agreement with the question asked.
The biggest farce is when pundits, or opponents of Obama Care make statements that the "majority" of American "people" are opposed to it.
Well, exactly what people were being polled? Republicans? Corporations? (since they are now deemed same status as individuals), Insurance companies? Certainly not an equal cross section of all party, or class, views.
If one listens to Fox News, CNN and MSNBC, all on the same day, it surely looks like we are listening to people who live on two different planets.
The haters believe Fox, the liberals believe MSNBC. The only thing that all can believe in is that what they hear on all of those news stations is one sided - they only present the negative and the ugly in our society and that makes people think that there is no decency left in this world.