Court cannot defer to impatient activists on King and Obergefell cases. It's spring in Washington, and time to resume one of the capital's favorite sports. No, not baseball, but throwing mud at the Supreme Court. Pending cases include the legal status of same-sex marriage and whether the IRS can provide billions of dollars in Obamacare subsidies without explicit congressional authorization. Partisans have launched a preemptive bid to undermine the legitimacy of the forthcoming decisions by accusing the court of "activism" for involving itself at all.

These increasingly transparent attempts to discredit the court should be rejected.Every case involving plausible abuses of power requires judicial engagement — conscientious, impartial truth-seeking, grounded in evidence — rather than reflexive deference to the political branches.

Take the Obamacare case. At issue in King v. Burwell is a section of the Affordable Care Act concerning tax credits for buying health insurance from government-operated healthcare exchanges. Congress wanted states to set up their own exchanges, but it lacks constitutional authority to force them. So Congress opted for a stick-and-carrot approach, authorizing tax credits for insurance policies purchased "through an Exchange established by the State." As a backup, the ACA directed federal bureaucrats to set up federally operated exchanges in states that declined to set up their own.

The question before the court is whether it was legal for the IRS to provide subsidies for policies purchased on federal exchanges, despite the lack of explicit statutory authorization. According to some critics, only a politically motivated court could answer no. But the language of the ACA is clear: "'State' means each of the 50 States and the District of Columbia." As Justice Kagan put it recently in another case, the court "has no roving license, in even ordinary cases of statutory interpretation, to disregard clear language." If the court disregards this maxim when deciding King, it will replace the rule of law with the rule of impatient executives and unelected bureaucrats.

There is general agreement among conservatives that the court should take a truth-seeking approach in determining whether the IRS is acting lawfully, rather than indulging in government-favoring speculation. But some of those sa me conservatives argue that the court should take a highly deferential approach in the same-sex marriage case, Obergefell v. Hodges, set to be argued on April 28.

In the opinion that is now before the court, the Sixth U.S. Circuit Court of Appeals found that excluding same-sex couples from marriage could be justified on any plausible grounds. The Sixth Circuit asserted that the government may treat people differently based on naked preferences for politically powerful groups, specifically citing "nepotism" as reason that would pass constitutional muster. Further, the court stated that government classification may rest on "rational speculation unsupported by evidence or empirical data."

As the Institute for Justice argued in its amicus brief, the Sixth Circuit's application of the "rational basis test" — the default test in constitutional law — was so utterly deferential that it would render the many constitutional protections subject to rational-basis review entirely meaningless. This includes everything from private property ownership and the right to earn an honest living to whether terminally ill cancer patients may have access to potentially lifesaving drugs. Americans deserve better.

Disagreement about the issues at stake in King and Obergefell should not be allowed to obscure the need for judicial engagement. The threat posed by unchecked government power is too substantial, its consequences too devastating. Those browbeating the court with charges of "judicial activism" and urging reflexive deference to the political branches are asking for the abdication of judicial responsibility.

The court should focus on making the right calls, rather than being swayed by voices coming from the bleachers.

Clark Neily and Evan Bernick direct the Institute for Justice's Center for Judicial Engagement.