The acting attorney general said such messages were “posted constantly” and said the Justice Department had gathered other evidence against the former F.B.I. director, but declined to describe it.
In a reversal, the Trump administration has exempted foreign physicians from a visa application freeze that was pushing many out of jobs in underserved areas.
A Times analysis of footage released by the F.B.I. on Thursday night appears to show the assailant shot at a Secret Service officer, who then returned fire.