There are those claiming that he can't. But there's nothing in the Constitution that prevents it. Only thing that has a firewall to it is in the one exception of impeachment. The president is expressly powerless to pardon himself from impeachment and removal from office.
Aside from that, there's nothing in the Constitution that prevents him from issuing a blanket pardon for himself, and pardoning anybody else he pleases.
If a president pardoned everybody, including himself, he would have a PR problem. He would look guilty. In order to escape his accusers, he would have to resort to this unprecedented move.
But Trump's case may be justifiable. This entire "investigation" was phony from the start. It is an excuse to remove the president from office. His accusers are only looking for this very excuse.
By the way, it has also been said that impeachment is a political act. The thing to remember here is that the legal process is being politicized. The president's critics want to appear to be legal in removing the president. By pardoning himself and his associates, Trump can take that out of his critics hands. But in doing so, he will have given them ammunition to remove him from power for purely political reasons. This escapes the phony show trial aspect, but it doesn't remove his risk of being removed from office. In other words, by disarming his legal accusers, he would arm his political ones.
All of it, pardons and impeachment, would be legal. After blanket pardons, it would become completely political. Furthermore, it would be better because it would put things on their proper foundation. This legal show trial game is part of a political campaign. Of course, Trump's critics will scream bloody murder, but they have been doing that already.
