and otherwise engage in interstate commerce to access this important medical care, and more would be forced to do so absent this Act. Likewise, health care providers travel across State lines and otherwise engage in interstate commerce in order to provide reproductive health services to patients, and more would be forced to do so absent this Act. (13) Health care providers, including those who provide abortion services, engage in a form of economic and commercial activity when they provide abortion services, and there is an interstate market for abortion services. (14) To provide abortion services, health care providers engage in interstate commerce to purchase medicine, medical equipment, and other necessary goods and services. To provide and assist others in providing abortion services, health care providers engage in interstate commerce to obtain and provide training. To provide abortion services, health care providers employ and obtain commercial services from doctors, nurses, and other personnel who engage in interstate commerce and travel across State lines. Abortion restrictions substantially affect interstate commerce in numerous ways. (15) It is difficult and time consuming for clinics to challenge State laws that burden or impede abortion services. Litigation that blocks one abortion restriction may not prevent a State from adopting other abortion restrictions or using different methods to burden or impede abortion services. There is a history and pattern of States passing successive and different laws that impede and unduly burden abortion services. (16) When a health care provider ceases providing abortion services as a result of burdensome and medically unnecessary regulations, it is often difficult or impossible for that health care provider to recommence providing those abortion services, and difficult or impossible for other health care providers to provide abortion services that restore or replace the ceased abortion services. (17) An overwhelming majority of abortions in the United States are