On the contrary, the precedent set by Obama's DOJ, absent any ulterior criminal motives by President Trump, would be a similar case involving a highly public figure grossly mishandling classified information. James Comey's FBI recommended no charges against Hillary Clinton and her staff. The reason being was because the FBI said those involved lacked "intent" to break the law.

https://www.fbi.gov/news/press-releases/press-releases/statement-by-fbi-director-james-b-comey-on-the-investigation-of-secretary-hillary-clinton2019s-use-of-a-personal-e-mail-system