When the IRS announced recently that it would not enforce a section of federal law commonly called the Johnson Amendment, many clerics rejoiced. The Johnson Amendment — named for its author, then-Sen. Lyndon B. Johnson — strikes a bargain with charities. You accept tax-free dollars, you stay out of the political arena.

The amendment is the federal law, codified in the IRS Code at 501(c)(3), that permits the IRS to grant tax-exempt status to qualifying charities. The tax exemptions generally permit the charity to solicit and accept financial contributions using pre-tax dollars, and relieves them from paying taxes on the income collected thereby. In return, the charity agrees to refrain from engaging in or financing partisan politics.

Most colleges and universities have this status, and nearly all religious institutions do. In many cases, local and state governments will grant their own tax exemptions, which generally exempt charities from paying real estate taxes on their properties and from collecting sales taxes on any goods that they sell.

Protestant ministers have often bemoaned the Amendment because they have longed for the ability to endorse candidates for public office publicly. Catholic priests have sought this as well, though the more traditional ones understand that recommending a political candidate from the pulpit has negative implications in canon law. Indeed, the United States Conference of Catholic Bishops — the governing body for American priests — recently indicated that it will adhere to the traditional understanding of the amendment, which means no public political endorsements.

What became of the Johnson Amendment? Since it is a federal statute, can the IRS abrogate it? Can the president pick and choose which laws to enforce and which parts of the laws to go unenforced?

Here is the backstory.

When James Madison was the scrivener at the Constitutional Convention in Philadelphia in 1787, he crafted the idea of the separation of powers. The separation mandates that only Congress can write the laws, only the president and those whom he hires to work for him can enforce the laws, and only the judiciary can decide what the laws mean and if they conform to the Constitution.

The flip side of the separation of powers is twofold. First, the separation prohibits any of the three branches from performing the core duties of either of the other two, whether by stealth, force or even permission. Core duties are those articulated in the Constitution or unambiguously derived from it. Thus, only Congress can impose taxes, as that core duty is assigned to it by the Constitution. This is essentially the reason that President Donald Trump’s tariffs have been found unconstitutional; a tariff is a tax, and only Congress can impose taxes.

The second flip side of the separation is the presumption that each branch will in fact do what the Constitution charges it with doing: Congress will write the laws, and the president will enforce them as they are written, and the courts will interpret them.

What happens if the president chooses to enforce laws only against certain persons but not against others arguably covered by the law?

That’s what happened with the partial abrogation of the Johnson Amendment by the IRS. The IRS works for the Secretary of the Treasury, who in turn works for the president. They are all part of the executive branch machinery charged with enforcing federal laws.

Presidents since Thomas Jefferson — even Madison himself — have succumbed to the temptation of choosing which laws to enforce and which to ignore.

Two weeks ago, Trump’s IRS publicly announced the upcoming selective enforcement of the Johnson Amendment.

Now the president can decide against whom to enforce the amendment by the public political speech of the 501(c)(3) charities. This, in turn, involves the government evaluating the content of speech — and that is prohibited by the First Amendment.