The Mr. Spock in us would like to see data as hard, fixed, and totally interpretable. The Dr. McCoy in us understands that data do not have those properties.
Nietzsche once wrote, "There are no facts, only interpretations." In fact we always interpret "facts" in light of our biases. Our filters come from our preconceived opinions. If we like something, we give great value to "data" that support that belief, while we de-emphasize the negative findings. Vice versa works also.
When you watch the debate, if you like Hilary Clinton, you will cheer her pronouncements and believe them true. If you like Donald Trump, you will dislike her statements.
Few viewers will look at the debate dispassionately. And thus those who claim fact checking are, in fact, not really unbiased either. They develop data that supports their preconceived notions.
We see this in medical debates: screening for prostate cancer, age to screen for breast cancer, whether or not to empirically treat some adolescent/young adult sore throats, the value of palliative care in cancer patients, etc.
A student recently reported a conversation he had with a program director. He asked her if her family medicine residents were exposed to direct primary care practices. She proceeded to scold him and anyone who would even consider such a practice.
In our society we too often disregard Steven Covey's admonition, "Seek first to understand, then to be understood." We will not see or hear this recommendation modeled in a debate, We rarely see this recommendation followed in medical debates. This recommendation requires civility, and that attribute has become much too rare.