"Due to recent attempted bombing attacks on current and former government officials (and others), there may be congressional interest in protective details for government officials. Congress may also be interested due to media reports of costs or budgetary requests associated with funding security details for the Secretaries of some departments or agencies,including the Department of Education, the Department of Labor, and the Environmental Protection Agency. Attacks against political leaders and other public figures has been a consistent security issue in the United States. Since the U.S. Secret Service (USSS) started protecting Presidents in 1906, seven assaults or assassination attempts have occurred, with one resulting in a death (President John F. Kennedy). Prior to USSS protection, three sitting presidents have been assassinated (Abraham Lincoln, James Garfield, and William McKinley). In addition, official records and news accounts show that there have been at least 20 attacks against Members of Congress since 1789."
CRS In Focus, IF10843
Congressional Research Service: https://crsreports.congress.gov/