By David B. Rivkin and Lee A. Casey

The unfolding IRS scandal is a symptom, not the disease.For decades, campaign-finance reform zealots have sought to limit core political speech through spending limits and disclosure requirements. More recently, they have claimed that it is wrong and dangerous for tax-exempt entities to engage in political speech.

The Obama administration shares these views, especially when conservative, small-government organizations are involved, and the IRS clearly got the message. While the agency must be investigated and reformed, the ultimate cure for these abuses is to unshackle political speech by all groups, including tax-exempt ones, from arbitrary and unconstitutional government regulation.

Beginning in March 2010, the IRS engaged in an unprecedented campaign of harassment against conservative groups, either through denials or delays in approving their tax-exempt-status applications, or through endless and burdensome audits.

In notable contrast, liberal and “progressive” organizations got approvals with remarkable speed. The most conspicuous example involves the Barack H. Obama Foundation, which was approved as tax exempt within a month by the then-head of the IRS tax-exempt branch, Lois Lerner. From media reports and firsthand accounts, we also know that the IRS disproportionately audited donors to conservative causes and leaked confidential tax information concerning conservative groups in violation of federal law.

This IRS politicization is not an isolated problem. It is an inevitable result of the broader efforts to regulate and, in fact, suppress political speech.

The IRS crackdown on tax-exemption approvals for conservative groups was directed at nonprofit social-welfare groups, often called 501(c)(4)s after the Internal Revenue Code section granting them tax-exempt status. Such groups do not have to disclose their donors and are exempt from most taxation, although donations to them generally aren’t tax deductible.

Social-welfare organizations are permitted to engage in a range of political activities promoting their causes or beliefs, so long as these activities aren’t their “primary purpose.” This has been generally understood to mean that they must spend less than 50% of their total resources on political activities.

The IRS had little interest in 501(c)(4) political activities until the 2002 McCain-Feingold campaign-finance reform. That law barred dedicated political-advocacy groups from soliciting and spending soft money—funds that aren’t subject to tight federal campaign-contribution limits and are used for issue advocacy and party-building.

This IRS restraint was doubtless reinforced by the fact that virtually all politically active (c)(4)s, mostly labor and environmental groups, were ideologically liberal and their activities were not attacked in the mainstream media or by the political establishment. Meanwhile, Republicans financed their political activities largely through candidate-specific campaigns and party and congressional committees.

Yet McCain-Feingold had the unintended effect of making 501(c)(4) political activities far more important than they had been, since the law’s ban on soft money doesn’t apply to such groups. Thus, it prompted the creation of conservative 501(c)(4)s—although there is little hard evidence of improper political activities by any such groups, whether liberal or conservative.

The Supreme Court’s 2010 decision in Citizens United further increased the importance of the groups by invalidating the restrictions against much political speech by corporations. This freed 501(c)(4) groups, which ordinarily are organized as corporations, to engage in the express advocacy of political causes and candidates.

The Obama administration made clear its deep dislike of Citizens United and of the various new conservative groups spawned by the “tea party” movement. The IRS bureaucrats took the hint. No express order from senior administration officials would have been necessary. Like other federal enforcement agencies, the IRS has always been well-attuned to even subtle guidance from the White House, Congress and the political establishment.

Thus, the IRS crackdown on conservative organizations was a direct and inevitable consequence of political and policy messaging by the Obama administration, and by the campaign-finance reformers who share these views. Congressional Democrats are also to blame, since many of them have publicly—as with Max Baucus, chairman of the Senate Finance Committee, which oversees the IRS—or privately urged the IRS to go after conservative tax-exempt organizations.

Ignoring their own share of responsibility, campaign-finance reformers and their allies are now pressing to broaden the IRS crackdown to apply to all tax-exempt organizations. In their view, the problem is not only with express political advocacy, but with all tax-exempt activities that might have political overtones, or be related to political issues. Indeed, many argue that such organizations should be conspicuously apolitical.

This is wrong as a matter of law and policy. Congress doesn’t have to provide tax-exempt status to social-welfare organizations, but having done so it cannot discriminate by the kind of advocacy in which such groups engage. To say that such activities can have no political implications is an insult to common sense. In a vibrant democracy, every major policy debate has political implications.

The spirited debate about policy issues should be at the core of social-welfare organizations. Politics is how we govern ourselves and political speech is essential to self-governance. The fact that 501(c)(4) group contributors aren’t subject to campaign disclosure requirements is a good thing.

There is nothing inherently evil about anonymous political speech. It is firmly anchored in our political and legal culture and was used by the Framers during the founding. Hamilton, Madison and Jay published their Federalist Papers under a pseudonym. The fact that the IRS was able to target conservative donors—similar to the way donors to the NAACP were targeted at the height of the civil-rights battles—shows how disclosure can lead to speech-suppressing government actions.

The courts have long held that the IRS cannot use subjective, “value-laden” tests in administering nonprofit status. As the Court of Appeals for the D.C. Circuit stated in one leading case, Big Mama Rag, Inc. v. United States (1980): “although First Amendment activities need not be subsidized by the state, the discriminatory denial of tax exemptions can impermissibly infringe free speech.”

The proper lessons of the unfolding IRS scandal are twofold. First, any effort to have the IRS police advocacy activities of social-welfare organizations is bound to be clumsy and prone to degenerate into either selective or broad witch hunts. Second, the remedy is not to further limit political speech by nonprofit entities—which would certainly raise significant constitutional issues—but to encourage such speech by imposing fewer restrictions.

Messrs. Rivkin and Casey served in the Justice Department during the Reagan and George H.W. Bush administrations. They are partners in the Washington, D.C., office of Baker & Hostetler LLP.