Editor's Note: (John R. Kasich is the former governor of Ohio, serving from 2011 to 2019. A Republican, he was previously a member of the House of Representatives. He is the author of "Two Paths: America Divided or United." The opinions expressed in this commentary are his. View more opinion articles on CNN.)
(CNN) During my 18 years as a member of Congress -- not so long ago -- my colleagues and I didn't robotically toe the line with the President. Republicans didn't vote in lockstep with Republican presidents, not even Ronald Reagan. And Democrats departed from their party's president when they thought it was the right thing to do. We took party loyalty seriously, but we gave even greater weight to principle.
In recent decades, of course, partisanship in the House and Senate has become far more intense, and the nation is worse as a result. But even now, in this hyper-partisan era, there comes a time when our elected leaders must put country over party.
One such moment: the ongoing debate over President Donald Trump's national emergency declaration to fund construction of a wall on the US-Mexico border. Sometime soon, Republican senators will have the opportunity to demonstrate -- as 13 Republicans did in the House -- their love of country and their commitment to constitutional values by voting for the resolution to disapprove the President's emergency declaration. Instead of acting like they're afraid of their own shadows, Senate Republicans must use this vote to -- at long last -- stand up and defend the Constitution.
Let's be clear. This vote is not about the situation at the border; it's about an executive power grab and, above all, congressional respect for the democratic process. Whatever their views on the border situation -- which I agree is serious -- Republicans should oppose the President's declaration. Standing against the President on this issue is important not just for today, but for our future.
For years, Republicans decried executive overreach by President Barack Obama. If we are serious about our constitutional values, we can't complain only about actions by the other party. We have to apply consistent principles whenever we have a president from our own party as well.
We should be especially concerned about President Trump's effort to circumvent Congress simply by invoking the magic word "emergency." If presidents can do end runs around Congress merely by claiming "emergency," then there's almost no limit to executive authority. This would create a gravely dangerous situation, not only for this president but for all future presidents as well.
Legal scholars are debating what the word "emergency" means as it's used in the National Emergencies Act, and the courts will resolve that question if Congress fails to override an expected presidential veto of their resolution of disapproval. But there's no real doubt about what the word is supposed to mean. A president's emergency powers are intended to be used for addressing sudden or unexpected events, not just serious problems. Indeed, the National Emergencies Act, passed in 1976, aimed to curtail -- not expand -- presidential discretion to declare emergencies.
What's also clear is how emergency declarations should be used: To address problems in ways for which there is not only a general consensus, but also where the pressing nature of the challenge requires speedy action without the formal and oftentimes slow process of congressional action. Nothing about the current situation matches up to that standard.
President Trump's emergency declaration for border wall funding is almost the antithesis of that model. The problems at our border may indeed be severe, but they are chronic. Even more significantly, there is not a consensus to pursue the President's approach. To the contrary, Republicans and Democrats in Congress did negotiate a compromise -- and the President signed it into law. But then he proceeded to turn his back on the negotiation, the process and the agreement by declaring a national emergency.
That kind of unilateralism not only conflicts with our Constitution, it amplifies the worst of our present-day politics. President Trump is playing to his base, focused on politics not policy. The result of his approach is more bitterness and alienation, less trust between parties and a continued loss of public confidence in our government. It leaves both parties -- our government -- far less able to do the things the American people need and desire.
I am proud to have joined with three dozen former Republican members of Congress to urge those Republicans currently serving there to stand for our values and by standing up to the President against his emergency declaration. President Trump remains popular within our party, but so is a deeply ingrained commitment to constitutional conservativism. Opposing your party's president is never easy, but I am hopeful that Republicans will vote to uphold the constitutional principles I know they hold dear.