“Your husband disagrees with you,” Donald Trump spat across the stage of the third presidential debate, interrupting Hillary Clinton’s defense of the Affordable Care Act.

Trump’s remark may not have phased her, but it did phase me.

The notion that her husband’s disagreement was supposed to discredit Clinton’s response appalled me. Bill Clinton isn’t on the ticket; why are his opinions being interrogated? Trump’s remark reeked of sexism as he attempted to silence a woman by invoking the authority of “the man of the house.”

Even though Bill Clinton is a former president, his position in the new administration will be as a spouse, not a policymaker. He doesn’t need to agree with his wife, and she doesn’t have to agree with him. Just as any other couple disagrees, first spouses haven’t always agreed with president’s views.

In 2010, former First Lady Laura Bush revealed that she supports abortion rights and gay marriage, breaking from her husband’s traditional views. Her statements neither discredited nor reflected poorly on President George W. Bush, his views or his time in office. Her politics were a non-issue, as any politician’s spouses’ ought to be.

Maybe Trump’s remark was easily overshadowed by his other outrageous comments: “nasty woman,” “bad hombres,” “rip the baby out of the womb,” the list goes on. But the lack of outrage about this comment across news outlets and social media scared me.

Degrading remarks have the potential to make the next generation of female leaders feel limited and lesser than male counterparts.

Lowering women’s self esteem always has real consequences, but even more so in politics. In discussions with women considering political careers, Senator Susan Collins found that potential female politicians are most often deterred by a lack of confidence, an article in the New York Times—“The Problem for Women Is Not Winning. It’s Deciding to Run”—revealed last week. Even Senator Kirsten Gillibrand, who dreamed of being a senator since her childhood, spent a decade building her confidence before running for office, the Times wrote.

This is a historic election. Hillary Clinton is the first female candidate from a major party, and in less than a week, she may become the first female president. Sexist rhetoric must be condemned now—by the media, by Secretary Clinton, by all of us—to set a precedent for how women should be treated, not only as presidential candidates, but as leaders.

Society has overcome some prejudices, but others remain, a fact Donald Trump has confirmed with constant, unapologetic sexism throughout his campaign. Refusal to accept his demeaning remarks—even those that may seem minor—is the only way to fight his mindset and society’s entrenched sexism.

Mr. Trump, women can be unapologetic, too. Yes, her husband disagrees—so what?