He got lucky that the sitting attorney general was loathe to appear that he was politically motivated, so was very slow to appoint a special prosecutor. He then got extremely lucky that his hand picked judge was assigned to the case, and slow walked it until he got reelected and took control of the very department that was investigating him.

This on top of the fact that the "law and order" party apparently is only for law and order if it's being used against people they don't like. Evidently most people aren't self aware enough to question their own beliefs, who knew?