During Mr. Trump’s first trip abroad in May, Ms. Trump raised eyebrows when she briefly represented her father at the Group of 20 meeting in Hamburg, taking a seat alongside Prime Minister Theresa May of Britain and Chancellor Angela Merkel of Germany. She was jeered when she called her father “a tremendous champion of supporting families” during a women’s entrepreneurship panel in Berlin. “Whom are you representing?” the moderator asked. “Your father as the president of the United States, the American people, or your business?”

It’s an apt question. Ms. Trump chose a formal, unpaid administration role, requiring her to comply with federal conflict-of-interest and ethics rules. Yet she and Mr. Kushner have retained financial control of their businesses and have made repeated errors on federal financial disclosures. CNN reported Thursday that the F.B.I. is investigating one of Ms. Trump’s business deals, in Vancouver. Other projects she has spearheaded, from Azerbaijan to Manhattan, have raised legal questions as well. She hawked her book on Twitter, and has used public appearances to tout Ivanka Trump-branded jewelry and showcase Trump family businesses.

Ms. Trump’s zeal for global renown has been exploited by foreign governments eager to curry favor with her father, just as her husband’s financial travails have been viewed as opportunities for influence. On the day Mr. Trump and the Kushners met with the Chinese president, Xi Jinping, China granted Ms. Trump’s company three trademarks in the giant Chinese market; other countries have done likewise.

But where are Ms. Trump’s public policy successes? Language supporting paid family leave appeared in Mr. Trump’s initial budget blueprint, which went nowhere in Congress. There have been executive orders and working groups promoting women in technology, apprenticeships and job training, but no significant government funding, programs or legislation. Her White House detractors deride Ms. Trump’s causes as a “pet agenda,” vigorously opposed by the Republican base her father strives to satisfy.

As Mr. Trump targeted undocumented immigrants, women, gay people and the poor, as he pulled out of the Paris climate agreement and tried repeatedly to deprive working families of health insurance under Obamacare, Ms. Trump defended herself, telling Gayle King, “I would say not to conflate lack of public denouncement with silence. … Where I disagree with my father, he knows it.” The interview earned her late-night-TV ridicule as “complicit” in her father’s atavistic policies. In another interview, Ms. Trump declared the Syrian refugee crisis a “global humanitarian crisis … we have to solve,” then evaded a question of whether her father’s travel ban, which, among other groups, specifically bars Syrian refugees from the United States, is part of the problem.

Last summer Ms. Trump toured the nation cheerleading for tax cuts that penalize working families while enriching her own family. A child tax credit she favored failed a key Senate vote after she skipped the debate over it, instead traveling to India for the Global Entrepreneurship Summit. After Mr. Trump blamed “many sides” for a violent neo-Nazi demonstration in Charlottesville, Va., in which a young counterprotester was killed, Ms. Trump, who converted to Judaism when she married Mr. Kushner, tweeted an anodyne rejection of “racism, white supremacy and neo-Nazis.” She said nothing more pointed than that about her father’s remarks, which caused C.E.O.s to bolt White House advisory boards.

During an interview when she was in South Korea, , Ms. Trump was asked whether she believed women’s accusations of sexual misconduct and assault against her father. Ms. Trump, a senior presidential adviser who profits personally from her support for women’s empowerment, took umbrage. “I don’t think that’s a question you would ask many other daughters,” she said, before going on to say she believes “my father.”

What a perfect summary of what’s wrong with White House nepotism. Since she is the president’s daughter, Ms. Trump considers herself immune from criticism or tough questions even when she’s acting in her public role as a “senior adviser.” In fact, of course, no policymaker truly committed to the agenda Ms. Trump espouses would have joined this administration. No presidential adviser with the values she claims would still be working for a president so determined to lay waste to them. So why does Ms. Trump stay? The answers could only be family allegiance, personal gain, or plans — wildly optimistic plans, in light of the F.B.I. noose tightening around this White House — for a dynastic political career. These are precisely what the founders condemned as nepotism’s dangers to democracy. Ivanka Trump isn’t serving America, she is serving the Trumps.