Gerard Baker, the editor in chief of The Wall Street Journal, has faced unease and frustration in his newsroom over his stewardship of the newspaper’s coverage of President Trump, which some journalists there say has lacked toughness and verve.

Some staff members expressed similar concerns on Wednesday after Mr. Baker, in a series of blunt late-night emails, criticized his staff over their coverage of Mr. Trump’s Tuesday rally in Phoenix, describing their reporting as overly opinionated.

“Sorry. This is commentary dressed up as news reporting,” Mr. Baker wrote at 12:01 a.m. on Wednesday morning to a group of Journal reporters and editors, in response to a draft of the rally article that was intended for the newspaper’s final edition.

He added in a follow-up, “Could we please just stick to reporting what he said rather than packaging it in exegesis and selective criticism?”