References to an undue burden standard are a shorthand to a collection of similar sounding, but legally distinct standards invoked in various areas of United States constitutional law. One version of an "undue burden" test was once widely used during the Lochner era of jurisprudence, in which courts invoked the concept of economic freedom to invalidate statutes. It is widely understood in the legal community that this era came to a end following President Roosevelt's 'court packing plan.'
Some areas of United States constitutional jurisprudence use tests described using terms like "undue burden," though the tests themselves exist in distinct areas of the law. The two most notable areas to use such tests are the areas of the Dormant Commerce Clause (e.g. United States v. Lopez) and abortion (e.g. Planned Parenthood v. Casey).
Some advocates have described the undue burden standard as "a 'middle way' forward" for Constitutional analysis, between the strict scrutiny and the rational basis tests.