Kamala Harris’ meteoric polling rise obscures her continuing weakness with black voters.

If she can’t cure this by Election Day, her path to win most of the key swing states will be in grave danger.

And her campaign is well aware of this potentially fatal flaw: That’s why her vaunted bus tour through southeastern Georgia stopped in black-dominated Liberty County and a local historically black college.

Savannah, the site of Harris’ final rally of the tour, is majority black and gave President Biden over 75% of the vote in 2020.

Black voters in Georgia and nationwide have been the mainstay of the Democratic Party for decades: Exit polls show that Democratic presidential candidates have carried them by at least 72 percentage points since 1980 — easily the largest margin for either party among a significant demographic.

Even Republicans’ margins among white evangelical voters, which has never been larger than 65 points, pales in comparison to Democratic domination of the black vote.

That’s why Harris’ current margins with black voters are cause for worry in her campaign: The Cook Political Report’s polling average shows her leading Trump 75% to 19% with blacks.

That 56-point margin would be magnificent with most demographics, but if replicated at the ballot box this November it would be the lowest margin recorded by a Democratic nominee among black voters since the passage of the Civil Rights Act of 1964.

Such an historically poor showing by Harris would be especially damaging in the swing states.

Black voters were 29% of Georgia’s electorate in 2020, and Biden carried them by 77 points. Harris would easily lose the state if she were to carry them by only 55 or 60 points this year.

They are particularly important to her hopes in the three Midwestern swing states. Blacks comprised 11% or 12% of all voters in Pennsylvania and Michigan in 2020, and Biden carried them by 85 points in both states.

The math is stark for the Democrats: Harris would lose Pennsylvania by about 1.5 percentage points if her margin with black voters is 20 points lower than Biden’s was.

A similar showing in Michigan would nearly erase Biden’s victorious 2.8% margin there, making her even more dependent on groups like the state’s large Arab population to see her through.

She would even lose Wisconsin, a much whiter state, if her current margin among black voters doesn’t improve. Blacks were only 6%  of the Badger State’s electorate in 2020, but Biden won them by 84 points en route to a narrow .63%  victory.

Harris will lose Wisconsin by about the same margin if she wins its black vote by “only” 64 points.

This means the contest for black votes is crucial for both candidates.

Trump has to keep the small but real gains he has made among black voters, while Harris has to win back these formerly staunch Democrats who have seemingly become disenchanted with the administration in which she serves.

That’s much easier said than done.

Only 56% of black respondents approved of Biden’s job performance in the most recent Economist/YouGov poll, and even fewer approved of his performance on the economy (51%) and immigration (40%).

It’s hard to see how Harris can sufficiently separate herself from her own administration to avoid being dragged down by these horrific numbers.

And it’s easy to see what Trump will argue: raw economic facts.

Government statistics show that black unemployment is higher today than it was during the pre-pandemic Trump years. Real wages, too, have been stagnant during the Harris-Biden administration for blacks employed full-time.

Trump can point to these numbers and remind black voters they had it better economically when he was president.

He can also point to the millions of immigrants admitted to the country in the last four years due to Harris-Biden policies.

Encounters at the southern border may be lower now, but the millions of migrants competing for jobs with many native-born Americans wouldn’t be here had Trump won re-election in 2020.

These facts suggest that sooner or later, Harris will try to inject race into the campaign.

Democrats have long played the race card to keep their astronomically high margins with black voters. It would be shocking if a black woman in the contest of her life wouldn’t resort to similar tactics.

One cannot know if that approach would work: It has in the past, but surveys show that younger blacks are much less wedded to the Democratic Party than their parents and grandparents were.

Sixty years after the passage of the landmark Civil Rights Act, with significant changes in the social and economic lives of African Americans, many don’t have the same personal imperative to back the party that pushed that bill into law.

Harris and her running mate, Minnesota Gov. Tim Walz, have so far traveled mainly to largely white communities in their effort to hold the Democrats’ Blue Wall.

Harris’ Georgia trip shows she knows she needs to make a play for the black voters her predecessors could take for granted. Much will ride on whether that final appeal succeeds.

Henry Olsen, a political analyst and commentator, is a senior fellow at the Ethics and Public Policy Center.