A quote from that link:
In the end, truth will out. Won’t it?
Maybe not. Recently, a few political scientists have begun to discover a human tendency deeply discouraging to anyone with faith in the power of information. It’s this: Facts don’t necessarily have the power to change our minds. In fact, quite the opposite. In a series of studies in 2005 and 2006, researchers at the University of Michigan found that when misinformed people, particularly political partisans, were exposed to corrected facts in news stories, they rarely changed their minds. In fact, they often became even more strongly set in their beliefs. Facts, they found, were not curing misinformation. Like an underpowered antibiotic, facts could actually make misinformation even stronger.
In an ideal world, citizens would be able to maintain constant vigilance, monitoring both the information they receive and the way their brains are processing it. But keeping atop the news takes time and effort. And relentless self-questioning, as centuries of philosophers have shown, can be exhausting. Our brains are designed to create cognitive shortcuts — inference, intuition, and so forth — to avoid precisely that sort of discomfort while coping with the rush of information we receive on a daily basis. Without those shortcuts, few things would ever get done. Unfortunately, with them, we’re easily suckered by political falsehoods.