The 14th Amendment to the United States Constitution was ratified 150 years ago—on July 9, 1868. It was one of the “reconstruction amendments” that were passed after the Civil War to fully and permanently abolish slavery and protect the rights of freed slaves, but its impact has extended far beyond the issues arising out of slavery and its abolition. Indeed, in terms of lasting impact, the ratification of the 14th Amendment is arguably the most consequential constitutional change since the founding era.

The amendment’s lasting impact stems primarily from a passage that appears in section 1:

No State shall make or enforce any law which shall abridge the privileges or immunities of citizens of the United States; nor shall any State deprive any person of life, liberty, or property, without due process of law; nor deny to any person within its jurisdiction the equal protection of the laws.

That passage gave the U.S. Supreme Court the power to strike down state laws that previously would have been beyond its jurisdiction. In the years immediately after ratification, the court showed some reluctance about exercising its newly acquired power (e.g., the Slaughter-House Cases and Plessy v. Fergusson). However, beginning early in the 20th century, and continuing ever since, the court has used its power under the 14th Amendment freely in a long series of controversial decisions, including:

Pierce v. Society of Sisters (1925) (striking down an Oregon law that banned private schools);

Brown v. Board of Education (1954) (striking down a Kansas law that permitted segregated schools);

Loving v. Virginia (1967) (striking down a Virginia anti-miscegenation law);

Roe v. Wade (1973) (striking down a Texas anti-abortion law);

Univ. of Cal. v. Bakke (1978) (striking down a California minority admission program);

Planned Parenthood v. Casey (1992) (striking down a Pennsylvania anti-abortion law);

Lawrence v. Texas (2003) (striking down a Texas anti-sodomy law); and

Obergefell v. Hodges (2015) (striking down laws in several states barring same-sex marriages).

The fact that the 14th Amendment gives the Supreme Court such wide jurisdiction over the states is one of the primary reasons appointments to the court are so hotly contested.

And the fact that Brett Kavanaugh will, if confirmed, get to exercise that power is one of the primary things motivating those who support, and those who oppose, his nomination.