Donald Trump’s decisive victory in this year’s presidential election overshadows a humbling fact: The next Congress will have a Republican Senate majority of 53 to 47 and a GOP House majority of 220 to 215.

That is the same number of Senate seats Republicans held during the final two years of Trump’s first term, and the narrowest House majority since 1930. The House GOP conference is expected to shrink further, at least temporarily, with the departures of Reps. Gaetz (R., Fla.), Waltz (R., Fla.), and Stefanik (R., N.Y.). Narrow margins will complicate Trump’s plans. Indeed, they already have.

Senate Republicans can lose three votes and still pass measures on the party line, with Vice President-elect J.D. Vance breaking ties. If no Democrat comes to Trump’s aid on the things that matter most to him—a safe assumption—then the president cannot afford to lose four votes on executive branch and judicial nominees, or on the reconciliation packages that will address the border, taxes, spending, and energy. In the ever more precarious House, Republicans will have to avoid any defections until special elections replace the members joining the Trump administration. House Republicans are not known for their unanimity.

Trump’s critics say that since his popular vote share has fallen below 50 percent—currently, it stands at 49.8 percent—he has no mandate. They are wrong. Trump’s mandate arises not just from the raw vote total, but also from the fact that every swing state, every part of the country, and major demographic groups swung toward Trump. The desire for change, and the swerve toward Trump’s views on the economy, immigration, and foreign policy, propelled Trump to the presidency as well as to newfound popularity. The Republican trifecta—control of all three branches government—reveals the public’s appetite for disruption.

But not too much. It did not take long after Election Day for the Senate to exercise its independent spirit. First, Republican senators, against the wishes of vocal Trump allies, chose John Thune of South Dakota to lead the majority. Second, Thune responded to Trump’s demand for across-the-board recess appointments for the executive branch by saying that the Senate would work overtime to confirm the president’s nominees. That’s Senate-speak for “No, thank you.”

Third, GOP senators made clear to the president-elect that his initial nominee for attorney general, Matt Gaetz, did not command majority support. Message received: Gaetz withdrew from contention and Trump replaced him with former Florida state attorney general Pam Bondi, who will be confirmed easily. Now there are murmurs from the Senate that Trump’s nominee for secretary of defense—veteran, author, advocate, and television host Pete Hegseth—might not have 50 votes either.

Hegseth, like Gaetz, is dogged by allegations, often anonymous, of personal misconduct. His nomination was thought to be doomed until midweek, when he launched a public relations counteroffensive.

Through social media posts, an interview with Megyn Kelly, a Wall Street Journal op-ed, on-the-record testimony from friends and colleagues, and meetings with congressmen and senators inclined to support him, Hegseth has said that he is the victim of a smear campaign. He pledges to be a secretary of defense for “warfighters, not warmongers.” He says that Trump has his back. Watching the proceedings unfold, you get the sense that Trump is testing Hegseth’s mettle. He’s waiting to see if Hegseth’s strategy delivers results.

I happen to like Pete Hegseth and think that, with the right deputy secretary, he would shake up a bureaucracy that desperately needs shaking, motivate recruitment, and be a voice for soldiers rather than brass. But I don’t have a vote. Senators do. And I can name more than three GOP senators who are unlikely to be convinced that Hegseth is, in the words of his mom, “redeemed, forgiven, changed.”

The question is whether Hegseth wants to keep fighting until a confirmation hearing, when he will have to face not only Republicans but also Democrats. Conversing with Roger Wicker, Dan Sullivan, and Joni Ernst is one thing. Subjecting yourself to Richard Blumenthal, Mazie Hirono, and Elizabeth Warren—and exposing your family to what they might have to say—is another. A combative and polarizing confirmation hearing can save a nominee, of course: Think of Clarence Thomas and Brett Kavanaugh. But it can also doom him. That was what happened to Robert Bork and John Tower.

The MAGA movement has rallied behind Hegseth not just because he is Trump’s pick, but because of its sense that if Hegseth follows Gaetz out the door, scrutiny will fall on other nominees—such as Kash Patel for FBI director, Tulsi Gabbard for director of national intelligence, Robert F. Kennedy Jr. for secretary of health and human services, and Lori Chávez-DeRemer for secretary of labor. Fight to the end over Hegseth, the thinking goes, and other MAGA warriors will slip through the Senate picket line. Abandon him, and none of Trump’s nominees are safe.

While there is something to this argument, it fails to recognize that a nominee’s success depends less on the intensity of his support than on his ability to win over individual senators. Republican senators seem inclined to vote for a Trump nominee they may disagree with ideologically, so long as that nominee carries no personal baggage. This is Hegseth’s problem. And no amount of office mail or phone calls or primary threats will change the mind of a senator who has six years left in his term or has decided to explore a career in the private sector. Those contemplating the puzzle of Trump’s tricky confirmation math may recall the story of the senator who, when he decided to retire, told a colleague that he was studying French.

Matthew Continetti is a senior fellow at the American Enterprise Institute and the founding editor of The Washington Free Beacon. For more from the Free Beacon, sign up free of charge for the Morning Beacon email.