Donald Trump is the undisputed king of MAGA, a cultural and political movement.

But today he becomes president of the United States, which is a republic, and republics do not have kings. In America, we abide by the rule of law. Even when the law comes for a popular app—TikTok—that the MAGA king likes.

I’ve been looking forward to this week. I invested time, money, and reputation convincing powerful friends of the dangers and corruption of the American left and the damage being done to our citizens, culture, and institutions. I encouraged them to speak up and call for reform.

I put the first million dollars into Elon Musk’s pro-Trump America PAC, and brought in others, although Elon ultimately funded most of it. I’m glad I did: Dozens of the smartest and boldest friends and acquaintances I admire, including Elon, led by President Trump, start work today. Many have already been pulling late nights for weeks.

We are about to witness a patriotic fireworks show of action unlike anything we have seen in D.C.; for many conservatives, this is the most exciting policy week of our lives. Eliminating bureaucracy with rumors of mass firings and other tactics. Tossing out huge portions of sclerotic regulatory morass that stifles innovation and our ability to compete with China. Confronting special interests in healthcare, accelerating scientific innovation, fighting massive fraud throughout our entitlement system, confronting radicalism and nonsense in government-funded NGOs, deporting dangerous illegal immigrants, and designating Mexican cartels as terrorist organizations. The list goes on.

To some, this day of triumph might seem the wrong time to sound a note of caution. But history reminds us that the seeds of self-destruction can be sown at the moment of our greatest victories.

Our founders had great wisdom in how they designed the Constitution, and its separation of powers. The other branches of our government have already weighed in on TikTok; Congress passed a bipartisan bill last year to force the app’s Chinese owner, ByteDance, to divest its U.S. operations or face a TikTok ban. Late last week, the Supreme Court upheld the law in a unanimous decision.

A friend in Hong Kong wrote to a group of us yesterday that he “saw the TikTok ban was off.” But Trump is not Xi Jinping. The massive penalties the law imposes on any company that makes TikTok available in their marketplace or provides it hosting services are still in place. As a legal and constitutional matter, Trump has just 90 days to delay their implementation if he can certify to Congress a sale is on the horizon.

Some, including ByteDance itself, have raised objections to restricting TikTok on the grounds of free speech. To be clear: The intent of this law is not to prevent American citizens from posting opinions on social media. It’s to prevent a foreign adversary from controlling that conversation and deciding what Americans see, influencing American culture and opinion on markets, politicians, and otherwise. We should not allow a Chinese-controlled TikTok any more than we would have allowed the USSR to own American TV or radio stations.

But it does not matter what I think. And now that Congress and the Supreme Court have weighed in, it also does not matter what Trump thinks.

Trump has proposed making TikTok a joint venture—with 50 percent U.S. government ownership. So, Mr. President: Strike a deal if you can. Use every bit of leverage you have. We’ll be rooting for that. But remember why TikTok refused to consider a sale after you issued two executive orders telling them that they had to, or when Congress said much the same.

ByteDance will never sell TikTok, because TikTok is not a social media app with normal corporate incentives; it’s a weapon. America is the target of that weapon.

And in the meantime, the law must take effect. Because in our republic, it is the Congress that writes the law. If President Trump disagrees, he can try to change Congress’s mind.

I could not be more excited for this administration; but in four years, it will be over. Perhaps it will have wielded the law against those who have transgressed it. I hope he will have transformed much about our government. But if in his zeal to fight for what he believes, the new president feels tempted to go out of legal bounds himself, it is everyone’s job—especially those of us who support him—to speak up and defend the Constitution.

Courage is a strength of the new administration. For many of my friends, it took courage to speak out against problems in society and in favor of Trump. If we speak with the same principles and courage we brought to the 2024 campaign, I’m confident the checks on the presidency will remain resilient, so that all our children and grandchildren inherit a nation of laws, indivisible, with liberty and justice for all.

Sometimes the news moves so fast, you have to look closely to recognize if you’ve seen it before. Check out Eli Lake’s new podcast, “Breaking History,” where he breaks down the news by breaking down history. Premiering January 22 on all podcasting platforms.