It’s been a series of surprises since President Joe Biden stepped down as the Democratic presidential nominee and Vice President Kamala Harris replaced him. Harris has surged in the polls . She draws campaign crowds that make Donald Trump jealous . Once-mordant Democrats are now enthused about their odds of beating Trump , the Republican nominee, in this year’s race for president.

Here’s a particular WTF moment: Voters suddenly seem to rate Harris higher than Trump when it comes to the economy. The latest monthly Financial Times poll finds that 42% of voters say they trust Harris the most to handle the economy, while 41% trust Trump the most.

That’s an eye-opener for a couple of reasons. First, voters consistently rated Trump higher than Biden on the economy, and Harris hasn’t done anything at all to distinguish herself from Biden on economic issues since Biden dropped out on July 21. Yet voters rate her 7 points higher on the economy than they rated Biden just one month earlier.

Second, voter attitudes on the economy have been the single most important thing Trump has going for him. As is usually the case, voters say the economy is their top political concern, and up till now, Trump has been their go-to candidate on the issue. If Trump loses that edge, it could doom his campaign.

On the surface, it’s a mystery why voters would suddenly rate Harris higher on the economy than Biden. There’s been no abrupt improvement in the economy in recent weeks. If anything, the latest employment and spending data shows a slowing economy rather than an accelerating one . Inflation maintains its slow downward trend, but the run-up in food and housing costs that has bedeviled consumers during the last three years is still there.

There’s one intriguing clue deep in the FT poll, however, that might explain Harris’s improved rankings on the economy. Sixty percent of respondents say that if Harris wins the presidency, she should adopt different economic policies than Biden. In an open-ended follow-up question, respondents mainly said they want Harris to find better ways of getting inflation under control.

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That represents good and bad news for Harris. The good news is that some voters seem to be allowing her a reset and exempting her from blame for the inflation they mainly associate with her boss, Biden. The bad news for Harris is that voters may expect a lot more change than she’s likely, or able, to deliver.

Harris hasn’t yet released her own set of policies, distinct from Biden’s, though her campaign says that is coming soon. Even so, there’s not a lot of room to differentiate herself from the man who soundly defeated her and several other candidates in the 2020 Democratic primaries. Harris can’t go left and embrace progressive policies she backed in 2020 , such as Medicare for All and a ban on fracking. That's because that would alienate the moderate swing-state voters crucial to winning the general election in 2024. She can’t go very far to the right, either, as that would turn off progressives and possibly dampen turnout.

Biden, it turns out, fashioned a set of Goldilocks policies that worked for liberal voters in the Democratic primaries along with more moderate general-election voters. His energy plan, for instance, promotes green renewables through powerful incentives without punishing fossil fuel users. On healthcare, Biden sought to improve the existing system instead of scrapping it and replacing it with a federal solution. On taxes, Biden wants modestly higher rates on businesses and the wealthy instead of wish-list items such as an unworkable wealth tax.

Harris’s challenge is to cultivate the impression (illusion?) that she's different from Biden, policy-wise, when in fact she won’t be very much. She might get some help from inflation, which is declining to the point that it probably won’t be an issue for the next president. If she comes up with some kind of snappy-sounding plan to bring prices down, she might end up getting credit for something that’s already happening without presidential intervention. She'll also benefit from a likely Federal Reserve interest rate cut in September, which will be modest but signal that more cuts are coming and borrowing will get cheaper.

Harris could also suffer if her differentiation campaign flops and voters start to see her as more of the same. Then again, voters might just be relieved that the 81-year-old Biden is out of the race, with the 59-year-old Harris seeming more energized and capable, whatever the issue.

A little bit of change and a little bit of youth might go a long way in 2024.

Rick Newman is a senior columnist for Yahoo Finance . Follow him on X at @rickjnewman .

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