With President Donald Trump floating the idea of declaring a national emergency at the southern border, there’s a big question in conservative circles regarding the legitimacy of such a move. Below we provide some points on the legality and judiciousness of declaring a national emergency.

According to Fox News’s Chris Stirewalt, “Trump most assuredly has the authority to declare a national emergency concerning matters of immigration. He has that authority because the Congress explicitly gave such power to the executive branch in 1976. In the wake of Richard Nixon’s reign, Congress still devolved its own authority to an executive branch that had just proven itself to be an unreliable custodian of liberty. … We don’t have enough test cases to know for sure, but the constitutional legitimacy of the law is dubious at best. Like our friend Judge Andrew Napolitano would say: ‘Legal but not constitutional.’”

NPR adds: “Some scholars of presidential emergency powers say there is next to nothing, at least procedurally, that Capitol Hill could do to stop Trump from exercising what lawmakers of all stripes agree is his right to declare a national emergency. … Congress had tried to remedy its lack of control over emergency powers in the mid-1970s, in a Washington rocked by the Watergate scandal. At the time, once a national emergency had been declared, there were neither time limits for its duration nor requirements for reporting to Congress. Congress’ reform effort was the National Emergencies Act of 1976. It requires not only that the president formally declare a national emergency but also that he or she cite the specific statutory authority the president sought to use. An emergency declaration would lapse after one year unless formally renewed by the president. … Should Trump decide to circumvent Congress by declaring a national emergency to build a border wall, he would very likely rely on a statute that lets him reprogram unobligated funds that Congress has appropriated for military construction projects.”

University of Texas, Austin School of Law professor Stephen Vladeck says, “Congress didn’t define what is and what is not a national emergency, so it’s hard to imagine what criteria a federal court could use in trying to decide whether a national emergency was properly declared or not.”

However, NPR adds, “If there were to be a court challenge, [Center for Strategic and International Studies’s Todd] Harrison says, it is not likely to be over Trump’s invocation of the National Emergencies Act. A more plausible challenge, he says, would be over whether the wall Trump wants the military to build is aligned with a statute that stipulates any reprogramming of military funds must be ‘to undertake military construction projects.’ ‘Border security is the responsibility of the Department of Homeland Security, not the Department of Defense,’ says Harrison. ‘So I think it is not clear at all that the declaration of a national emergency here would actually allow the administration to use military funding for a nonmilitary purpose.’ Ultimately, Harrison says, it may be the landowners and local officials affected by the wall’s construction who would have legal standing to fight it in court.”

On that note, columnist Rich Lowry says: “Although declaring a national emergency sounds frightening, there is ample — indeed absurdly extensive — precedent for it. The nation is awash in more than two dozen, little-noticed declared national emergencies. So we have room for a national emergency at the border. The next step, which would presumably be reallocating military funds to building the border fence, is trickier. The administration can perhaps rely on statutes enabling the president to spend on military-related construction under his emergency powers. Yet no one to this point has thought of the border fence as a military project. It has been built up over the years with civilian funds by civilian workers. Yes, the National Guard and, at the moment, the active-duty military have been deployed to the border, but in a logistical or backup role, and largely as symbolism. The border crisis is not amenable to a military solution.”

Lowry goes on to note: “Legalities aside, a declaration of a national emergency won’t achieve what Trump wants, unless his goal is simply getting out from under the shutdown. That’s easy. He can say he’s going it alone under his emergency powers and agree to open the shuttered parts of the government, then fight it out in the courts. But in terms of his substantive goal of building a fence, and his political goal of building enough of it to showcase in his 2020 re-election campaign, it would get him very little. A district court somewhere would immediately issue an injunction blocking the action. Once the administration gets to the Supreme Court, it might have a chance to prevail if the court concludes that it shouldn’t second-guess the chief executive on questions related to national security. But when would such a decision get handed down? Sometime in 2020? Assuming Trump wins at the high court, it would take time to get anything going on the ground. Progress on the fence probably wouldn’t be any more advanced by November 2020 than it would be otherwise, and perhaps less advanced than if the president simply got some inadequate compromise out of Congress. In a different world, Congress as a body would be more exercised about a potential emergency declaration, but Congress is not a self-respecting institution. It is still a mistake to try to take advantage of its laxity. Such a move would strain our system, and probably not even work.”

Meanwhile, the editors at National Review argue: “The proximate cause of the attempt to redirect funds under emergency powers wouldn’t be radically new circumstances at the border. There has been a simmering crisis there for a long time. It would be a failure to get Congress to appropriate the funds the president wants during a political fight and negotiations. Legalities aside, this would be a very bad practice. It’s an offense against the spirit of our system for a president to fail to get he wants from Congress — in a dispute involving a core congressional power, spending — and then turn around and exploit a tenuous reading of the law to try to get it anyway. We know this seems increasingly quaint, especially after President Obama’s pen-and-phone governance in his second term, but we believe presidents have an obligation to honor the role of the respective branches of government, even when it’s not in their political interest, even when there seems to be a clever workaround.”

The editors conclude: “An attempt to spend unilaterally on the fence would almost certainly get tied up in the courts immediately. In the most favorable scenario for the administration, it eventually prevails in a Supreme Court loath to second-guess even dubious military-related determinations by the commander-in-chief. In the meantime, the administration will have built nothing new on the border and created another precedent for unilateral government sure to be exploited the next time a Democrat occupies the White House.”

As you can see, this is a very complicated issue, and it would be prudent to leave room for nuance. Moreover, Trump deserves accolades for his devotion to finally addressing the issue and not just regurgitating talking points during stump speeches. However, as Thomas Jefferson warned, “Power is of an encroaching nature and … it ought to be effectually restrained from passing the limits assigned to it.” On that note, Sen. Marco Rubio observes, “If today, the national emergency is border security … tomorrow the national emergency might be climate change.” The bottom line is that, assuming Trump even has the authority to declare an emergency, the activist courts will leave no stone unturned, similar to the way they tried to derail the president’s travel ban. Republicans will fare better if they compel Democrat obstructionists to acquiesce by convincing the American people that the Left couldn’t care less about keeping them safe.