After the commentators stopped rolling their eyes and clucking about President Donald Trump’s national-emergency news conference last week, a sobering realization settled in: Trump may win in court. The 1976 National Emergencies Act is broadly, which is to say badly, written; it does not define “emergency.” Possibly, the courts will step in and stop the president from doing an end-run on Congress’ power of the purse in order to build his wall along the border. But the Supreme Court, whose conservative majority has an expansive view of executive power, could well uphold the president’s declaration.

So is it time to wring our hands about the decline of democracy and the rise of authoritarianism? No, at least not yet. A better way to think about the current mess is this: Let the system work.

It is tempting to compare Trump with Richard Nixon, the last president who flaunted executive power until he created a constitutional crisis. While more cerebral and far better-read than Trump, Nixon was subject to even scarier mood swings. But, his occasional rants notwithstanding, Nixon understood that presidential power is not absolute. True, during a 1977 interview with David Frost, he memorably said that “when the president does it, that means that it is not illegal.” But when he made this seemingly “l’etat c’est moi” declaration, he wasn’t saying that presidents could break any law they wanted with impunity. Frost had asked about the president’s power in “certain situations.” Nixon was saying that the president could act to protect national security in time of war or from a “threat to internal peace.”

Under the National Emergencies Act, Trump will certainly make similar arguments, and he may persuade the Supreme Court to take his side. But that is hardly the end of it. We like to think of the Supreme Court as “the last word,” but actually it is part of a larger, ongoing conversation. Congress, if it chooses, can amend the National Emergencies Act, to limit the executive’s authority under the act. The lawmakers may have to override a presidential veto to get that done, but they have the power to do that. And, at the next election, the voters, if they choose, can remove Trump from office. That is the way the system is supposed to work.

It can work slowly, and not always with the outcomes one group or another, including majorities, might want. I have just completed a biography of Sandra Day O’Connor, the first female Supreme Court justice, who sometimes frustrated her judicial colleagues by refusing to make the court the final arbiter of deep-rooted disputes. With her narrow, fact-based opinions, she would limit court rulings, sending a message to the lower courts and other government bodies, in essence, to keep trying. A former state legislator, she recognized that really hard questions, such as abortion and affirmative action, cannot be quickly and finally resolved, but need to be worked out over time through a prolonged interaction between the branches of government.

O’Connor had ultimate faith in the checks and balances among lawmakers, the political parties, the media and all the actors in our centuries-old national drama. Hers was a kind of civic religion, a belief that the system will work, if we just allow it to.

In the end, Nixon bowed to the system. Yes, he forced the Justice Department to fire the special prosecutor, Archibald Cox, appointed to investigate his crimes, but Nixon quickly acquiesced to the appointment of a new special prosecutor, Leon Jaworski, who proved to be no less determined to uphold the law. Yes, Nixon argued “executive privilege” and resisted turning over the White House tapes. But when the Supreme Court ruled against him - 9 to 0 - he turned over the tapes, including the “smoking gun” tape showing him obstructing justice. Resignation came a few days later.

Will Trump eventually go along if the courts and Congress deny him his wall? My guess is that he will, after a lot of bluster. By the same token, will his critics back down if he wins in court and accept this judgment, as they should? There will be a lot of talk - fanned by Trump himself, who has referred to Neil Gorsuch and Brett Kavanaugh as “my justices” - that the court is political. The justices can certainly be ideological. But over the long run, the independent judiciary has been a force for upholding the Constitution - for equal justice under the law.

What matters here, really, is not the personality of the president. In our system, all presidents are replaceable; they can be impeached or voted out of office. We cannot change the human weaknesses of our leaders. But we can count on the system that protects us from their failings.

Evan Thomas is the author of “First,” a biography of Sandra Day O’Connor, which is scheduled to be published in March. He wrote this article for the Washington Pos.