Abortion is a highly-charged and intensely-debated issue. Partisans on both sides believe abortion implicates fundamental human rights, with abortion supporters comparing abortion prohibitions to slavery, and abortion opponents comparing a permissive abortion regime to the holocaust. Some people believe so strongly that abortion should be available that they endure protests, threats, and physical violence to provide a service they deem critically important. Others refuse to refer or provide for abortions under any circumstances.