Capitol police say 33-year-old James McIntyre assaulted U.S. Rep. Nancy Mace of South Carolina.
Mace has made headlines and faced protests for her proposal to ban transgender people from using restrooms corresponding to their gender identity on Capitol Hill.
Mace tweeted on Tuesday night that she will be OK.
The Capitol was open to the public at the time of the incident.
McIntyre is charged with Assaulting a Government Official.