Ivanka Trump recently got a new official federal position in the West Wing of the White House, signaling the power she wields within its corridors. Republicans think highly of her — enough that she improves their view of President Trump. But apparent unease about her informal power among independents and Democrats may check her usefulness as an ambassador to the public.

That’s what I found from a recent survey.

Ivanka’s praise improves Trump’s public image — among Republicans

In early March 2017, I asked 4,044 survey respondents recruited through Amazon’s Mechanical Turk to read text described as an excerpt of a speech praising President Trump. The text was attributed to either Donald Trump, Ivanka Trump, Melania Trump, or Mike Pence, accompanied by a picture of the speaker. The text claimed that Donald Trump is a great leader who is keeping his campaign promises and making the country stronger.

After seeing the quote and accompanying picture, respondents answered questions about their attitudes toward the president. That included whether they approve of the job Trump is doing as president; how they feel about him; whether he “is intelligent,” and whether he “is a strong leader.” To assess their feelings about Trump, respondents were asked to evaluate the president on a scale of 0 to 100, where ratings between 0 and 50 degrees suggest respondents don’t feel favorable toward the president and don’t care too much for him, a rating of 50 indicates respondents feel neither warm or cold toward the president, and ratings between 50 and 100 indicate respondents feel warm or favorable toward the president.

In the figure below, you can see what the Republican respondents thought. Attributing the speech to Ivanka, rather than to Trump himself, significantly boosts opinion of the president among Republicans.

Ivanka Trump also boosts Republicans’ opinions of Trump significantly more than Vice President Pence does — by five to seven percentage points — especially on whether respondents think the president “cares about people like me,” “is intelligent,” and “is a strong leader.” Ivanka boosts Republican approval of her father significantly more than Melania Trump does, although Ivanka and Melania have an indistinguishable effect on Republican opinion of Trump on other measures.

This is a convenience sample, so I cannot be certain that the results represent how all Republicans would respond to Ivanka. For instance, the GOP respondents in my sample are somewhat younger than Republicans nationally. But I do find that the results are the same when I compare respondents above and below the age of 50.

But she doesn’t seem to help with independents or Democrats

The fact that Ivanka produces a more positive response than the president among Republicans is impressive, considering that he remains well-liked by Republicans.

But more Republican support isn’t what the president needs. To boost his falling approval ratings, he must find a way to appeal to non-Republicans. Most results among Democrats and independents in this experiment were not statistically precise enough to clearly determine how much Ivanka’s comments affect attitudes toward her father.

However, the results among independents and Democrats are consistently negative, meaning that Ivanka most likely worsens opinion of President Trump among these groups. In fact, independents who read Melania Trump’s purported praise evaluated President Trump significantly more positively than those who read Ivanka’s when asked to evaluate the president’s honesty and intelligence.

First ladies have traditionally served to soften an administration’s image

In past administrations, first ladies have been presidential administrations’ ambassadors to the public. First ladies historically burnish their husbands’ reputations by appearing to rise above the partisan fray, positioning themselves as apolitical Washington outsiders, and building positive rapport with journalists — all of which they use to appeal to citizens across the political spectrum. On the campaign trail, Melania Trump appeared to be able to increase opinion of her husband among independents when compared to other high-profile surrogates. Now more than a year later, her impact on opinion of Trump is more difficult to determine.

So can Ivanka step in? Maybe not. In recent polling, Americans showed mixed feelings about Ivanka Trump’s heavy involvement in her father’s administration. Only 45 percent of Americans said they want Ivanka to play an active role in the White House. That may be because Ivanka Trump’s power is mostly rooted in a personal — in fact, familial — relationship with a powerful person.

That’s the kind of power that makes government watchdogs and strict constitutionalists squirm: informal, unofficial power, unchecked and opaque, evading the rules put in place to restrain the human tendency toward dynasties over democracies. Many Americans were similarly uncomfortable in the 1990s about President Bill Clinton putting his wife Hillary in charge of a national health care bill.

That kind of personal power has been on full display, as the first daughter has sat in the president’s Oval Office chair, participated in official meetings with representatives of foreign governments, and actively pursued her own legislative agenda to support working women.

Ivanka may not succeed as the administration’s ambassador to the Americans who did not vote for her father. But for shoring up or exciting Trump’s base, there may be nobody better.

Lauren A. Wright, who will be teaching politics at Princeton University this fall, is the author of “On Behalf of the President” and a board member of the White House Transition Project. Follow her @drlaurenawright.