A Texas man, ranting on social media about the congressional response to the coronavirus outbreak, has been charged with making death threats to Speaker Nancy Pelosi and other Democrats, federal prosecutors announced on Thursday.

Gavin Weslee Blake Perry, 27, of Wichita Falls, Texas, wrote on his personal Facebook page on Monday that Ms. Pelosi was part of a satanic cult and that she and other Democrats should be killed, the authorities said.

The posts were still online as of Thursday night.

Prosecutors said that Mr. Perry wrote, “If youre a dem or apart of the establishment in the democrats side I view you as a criminal and a terrorist and I advise everyone to Go SOS and use live rounds.”

The post, which used an abbreviation for “shoot on sight,” included a screenshot of what appeared to be two tweets by Senator Chuck Schumer of New York, the Democratic leader. One, by Mr. Schumer himself, was critical of President Trump’s handling of the health emergency.