What does it tell us that Nikki Haley is drawing a sizable slice of the GOP primary vote despite suspending her campaign? We don’t want to overstate the erstwhile UN ambassador’s showing. She has, though, drawn some 20 percent of the votes cast so far — including 16.5 percent in Pennsylvania and 17.8 percent in Arizona, two swing states that voted after she left the race. Are these results best seen as a worry for President Trump — or an opportunity?

This is no small thing. In an election that will come down to “swing-state contests that could be decided by razor-thin margins,” the Wall Street Journal reports, Mrs. Haley’s persistent base of support in the GOP could be decisive. It is prompting renewed speculation about whether she will endorse Mr. Trump — and even whether, contrary to his protestations, she might emerge as his running mate. Mrs. Haley hasn’t signaled she’d back Mr. Trump. 

When Mrs. Haley suspended her campaign, though, she did urge Mr. Trump “to earn the votes” of those in the party who’d backed her candidacy. “Politics is about bringing people into your cause, not turning them away,” she said then. Yet just weeks ago, Mr. Trump’s campaign put out a digital ad featuring personal attacks on Mrs. Haley, including his obnoxious nickname for her — “birdbrain” — and his claims that “she’s not presidential timber.”

Despite claims by some critics that Mrs. Haley is racking up votes from Democrats meddling in the Republican nomination process or seeking to undermine Mr. Trump’s march to the nomination, in two closed primary states — Maryland and Nebraska — she earned 22 percent and 18 percent of the vote, respectively. The primary vote today in the Bluegrass State’s GOP primary could provide further evidence of this trend.

Far be it from us to lecture Mr. Trump on how to win a presidency, but it’s hard, from our perch, to see how his Haley strategy is going to help him in a close race. It could even create an opening for President Biden. “Donald Trump made it clear he doesn’t want Nikki Haley’s supporters,” Mr. Biden says. “I want to be clear: There is a place for them in my campaign.” That strikes us as exceptionally unconvincing. 

Mrs. Haley’s causes, after all, include fiscal responsibility and a robust American foreign policy. Mr. Biden hardly beckons. Yet a report today in Bloomberg Businessweek underscores why the more moderate voters who are a natural constituency for Mrs. Haley could be wary of backing Mr. Trump. Many of such voters, the report reckons, fear that “if Trump returns to the White House,” he’d “refuse to step down when his term is up.”

The concern is “showing up in our focus groups,” says Republican strategist Sarah Longwell. “Trump’s own provocations,” Bloomberg reports, “appear to be driving the fear of a permanent presidency.” The “obvious example” is the Capitol riot on  January 6, Bloomberg says. Pollsters “are probing to see how widely this sentiment has spread,” Bloomberg adds, especially among “undecided voters likely to sway the election.” 

The concern for the GOP, Bloomberg bruits, is that these worries are “pushing some undecided voters toward Biden.” That, Bloomberg explains, is despite the “significant reservations about the incumbent’s age, turmoil in the Middle East and high inflation.” More broadly, the abiding support for Mrs. Haley in the GOP suggests the upside of her keeping her options open in the weeks and months leading up to the election. 

After all, Mrs. Haley’s observation that “our conservative cause badly needs more people” rings as true as ever. While a Haley-Biden matchup is no longer being surveyed, her lead in polls against the incumbent often exceeded Mr. Trump’s. That is at least up until early March, when her campaign ended. While Mr. Trump’s nomination currently has the air of inevitability, the logic is for Mrs. Haley to keep her non-campaign-campaign active.