@mystery-ak Newt is just spinning a tale - he knows better than that.
Every candidate for state office and up, hires an Opposition Research company. Newt has done that many times. If you are running for office and have an opponent, you need to know his/her background so you can compare than person to you in order to determine why you would be better for that office than the other person. That is completely legal and necessary for you know who you are running against.
I knew the owner of the finest opposition research company in Texas. His company was in Austin. Not only did he do opposition research, he also had the history of voting in every county. He could help the candidate know where each county stood in terms of Democrats and Republicans and how that county voted for many years. I used his method of determining that and did it for my county. Then, I sent my results to him and ask if I did that right. He informed me I was exactly correct. He would have hired me had I lived in Austin.
Both Clinton and Trump hired opposition research companies. It is the results of those companies, not the candidate, who is responsible for what they found. Both Clinton and Trump are trying to hang those results on each other rather than the companies. That is what Newt is doing - saying Hillary did it, instead of the company.
I had to do a book proposal and part of that is opposition research - how is my book different from other books? Why is my book better than others? The only way to know that is examine those other books and contrast them to mine. That is opposition research.
This yelling back and forth now from the two sides, and their supporters such as Newt, that the candidate did it, is totally wrong but it makes news. The two opposition research companies have been named, but that seems to go by the wayside as blaming the candidate is what the other side wants to do.