Hoyer, speaking on CBS News' "Face the Nation" Sunday made the observation concerning the massacre of six people and the wounding of up to 20 others in Tucson Saturday.
"I don't think there's any doubt but my colleagues are very concerned about the environment in which they are now operating," Hoyer said. "It has been a much angrier, confrontational environment over the last two or three years than we have experienced in the past. And I think there is worry about that. I will tell you also that the staffers -- we should not forget that a staff member was lost here."
Rep. Gabrielle Giffords, D-Ariz., was shot through the head in the rampage and was in critical condition after brain surgery. A member of her staff was killed in the incident.
Police arrested Jared Lee Loughner, a 22-year-old Tucson college dropout who has posted rambling comments on the Internet, in the shootings. They were looking for a second man they think might be involved in Saturday's shootings.
Earlier Sunday Speaker of the House, John Boehner, R-Ohio, said Saturday's shootings were an attack on democracy.
"I share Speaker Boehner's view and the views that have been expressed by the two United States senators," Hoyer said. "This is not simply an attack on Ms. Giffords. This is an attack on democracy itself, on the ability, as she said in that reading of the First Amendment, to peaceably assembly, to come together to talk to one another."