"Everyone is entitled to his own opinion, but not his own facts." - variously attributed to Daniel Patrick Moynihan, James R. Schlesinger, or others

Big Data, that mushy phrase which represents having more data, more computing power to analyze the data, and/or more tools for accumulating data from multiple sources, has rendered obsolete this old phrase. There is now more data out there, than the human mind can ingest. Once you know your opinion, you can get all the facts you need to support it.

I realize there are some exceptions, but not very many important ones. Climate change, fiscal austerity, peak oil, free trade, or nearly any other controversial topic, now has so many relevant facts available for discussing it, that any sufficiently motivated person can get all they need. More than enough to fill any conversation or argument, which functionally means that debating is now an even more useless method of deciding a topic than it used to be. So you have a lot of facts on your side; good for you. All it proves is that you're a zealot who spent a lot of time with your favorite search engine.

Or, perhaps, you're a rich person or institution who can pay others to collect facts for you. Ever notice how the interests of the wealthy always have lots of columnists ready to defend them? The fact that you know a lot of facts in support of a position, may be more evidence of how many wealthy people want you to know those facts and not others, than it is evidence that the position is correct. We have so many facts, that inconvenient ones can be drowned out in a sea of others, if someone with money to pay for that sea of facts wants to.

What still should work, though, is prediction. If you make a prediction, and it comes true, then your mental model of how things work is still likely correct. This is especially so if you can make repeated predictions. In essence, a prediction is a way of saying which facts will be decisive, ahead of the time when it is known whether those facts will support your position or not. If you can make successful predictions, and I hear them beforehand, then I may think more of your position. If you tell me about your predictions afterwards, I am still not impressed, as many psychics can make enough predictions to have at least a few come true.

So, think not so much of facts, now, the quantity available has diminished their worth. Only (successful) predictions are evidence in favor of your position, and then only if your prediction seemed controversial at the time you made it.

That is, of course, just my opinion.