During his big speech yesterday at Howard University, Sen. Rand Paul (R-Ky.) repeatedly highlighted the Republican Party’s central role in drafting and ratifying the 13th, 14th, and 15th Amendments to the U.S. Constitution. While it’s not exactly a groundbreaking position nowadays to come out in favor of the 13th or 15th Amendments, Paul’s endorsement of the 14th is a more notable story.

Ratified in 1868, the 14th Amendment declares, “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 language empowers the federal courts to review the actions of state and local governments, and to strike down any such actions that violate fundamental rights, including those rights spelled out in the Bill of Rights. As Ohio Congressman John Bingham, the author of the words quoted above, explained in a speech to the House of Representatives, the rights protected by the 14th Amendment “are chiefly defined in the first eight amendments to the Constitution.”

Put simply, the 14th Amendment protects individuals against overreaching state and local governments. Here’s how Rand Paul summarized his views on that amendment yesterday at Howard:

Many Republicans do believe that decentralization of power is the best policy, that government is more efficient, more just, and more personal when it is smaller and more local.

But Republicans also realize that there are occasions of such egregious injustice that require federal involvement, and that is precisely what the 14th Amendment and the Civil Rights Act were intended to do--protect citizens from state and local tyranny.

That position is consistent with the text and history of the 14th Amendment. But it differs dramatically from the interpretation of the same amendment favored by Rand Paul’s father, Ron Paul.

In 2005, for example, shortly after the Supreme Court handed down its notorious decision in the eminent domain case Kelo v. City of New London, where the Court allowed a local government to seize private property on behalf of a private developer, Ron Paul argued that while the property should not have been taken, “the Supreme Court should have refused to hear the Kelo case on the grounds that the 5th amendment does not apply to the states.” According to Ron Paul, “The issue in the Kelo case is the legality of the eminent domain action under Connecticut law, not federal law. Congress can and should act to prevent the federal government from seizing private property, but the fight against local eminent domain actions must take place at the local level.” As for the idea that the 14th Amendment extends the Bill of Rights to the states, Ron Paul declared, “we must reject the phony incorporation doctrine in all cases.”

So while Rand Paul says that the 14th Amendment was designed to “protect citizens from state and local tyranny,” Ron Paul thinks the federal courts have no business enforcing the 14th Amendment at all.

This is not a mere academic difference. Consider the issue of gun rights. Under Ron Paul’s preferred approach, the Supreme Court would never have decided the landmark 2010 case McDonald v. Chicago, where the majority held that the Second Amendment applies to the states and therefore struck down Chicago’s handgun ban. Rand Paul, on the other hand, has praised McDonald as an example of individual rights properly triumphing over majority rule.

Time will tell if this is the only major difference over the meaning of the Constitution we'll find between father and son.