The Donald has nothing to hide from investigators. A person with nothing to hide should welcome an investigation which would show that Trump and his associates have done nothing wrong. The Donald is not behaving like an innocent person. His team of lawyers is trying to discredit those who are investigating him and his team. They discovered that some of the prosecutors on Mueller's team might even be Democrats. Mueller, who is a lifelong Republican, and one of the most respected law enforcement officers in America, apparently should not have recruited highly respected prosecutors who are also Democrats. The Donald's team is even looking into ways that Trump can use his pardoning authority to defend anyone, including himself, who might have broken the law. This is not the way a person with nothing to hide would typically behave. On the other hand, this is The Donald's typical mode of operation. He has a long history of attempting to discredit his numerous critics and political opponents. He also has no respect for the truth. The Donald is preparing his supporters for any bad news that might be discovered in the investigation. They should not believe what was uncovered by the "discredited investigators".
The Donald granted the NYT an exclusive interview that he used for a variety of purposes in response to the investigation that is underway. He warned Mueller that he might fire him if he goes too far in his investigation. Mueller, of course, is exploring any financial relationships that he and his team might have with Russian bankers, oligarchs and Kremlin officials. They might be related to possible collusion and they are also a national security concern. They could be used to influence Trump's foreign policy decisions. Trump also threw his Attorney General under the bus. He may want him to resign so that he can replace him with someone who could offer more defense to him than Jeff Sessions who has recused himself from the Russian investigation.
The Donald swore an oath to protect the Constitution when he was sworn into office. He spent most of his business career using the legal system for personal advantage. He is doing the same thing as our president. He is using the legal system to fight against the Constitution that he swore to protect.