The latest poll in Michigan (and not one that historically supports Trump) shows in Michigan that Trump is leading over Kamala Harris by 1%.
So that part, at least, of the poll you cited is already obsolete. Asssuming i was believable in he first place

Since it comes from the Democrat/Left partisan site...
https://newrepublic.com/post/184489/new-poll-conservative-group-disaster-trump-kamala
...I have my doubts.

Because Kamala Harris is not Joe Biden, and because she has a pulse, her poll numbers went up among the Democrat base when she became the nominee. That is just the Democrat base. She is not attracting independents or Republicans.
She is expected to get a temporary rise in polls following the Democrat convention this week. But after that, her numbers are expected to drop, as Kamala Harris and Tim Walz's records and actions and public statements over many years become widely known. At some point, Kamala has to stop hiding in the bathroom, give press conferences, and answer questions about her record, and about both her and Walz's leftist radicalism.

While the Nov 5h election is not in the bag for either candidate, Harris' temporary bump is expected to fade, as Harris and Walz are exposed as hard-Left fanatics who if able to succeed Biden, would continue to damage the country. Open borders, trillions in deficit spending, rampant escalation in crime, Democrat foreign policy weakness that invites escalation in Ukraine, Israel, Taiwan and North Korea, potentially thousands of terrorists already inside our borders and thousands more pouring in every day by Biden/Harris policy.
Policy that crushes businesses and leads to even further job loss. Even far-left companies like Google, Facebook, Amazon and Starbucks have had massive layoffs. I've seen economists predicting a stock market crash and a depression if Kamala Harris were to win.

Trump has said (I think accurately) that it is only the hope that Trump will win the election that is preventing the market from crashing.

For all the Democrat-subservient media's hype about a "lead" by Kamala Harris, the polls are largely unchanged, even among liberal polls such as the N Y Times.
https://www.realclearpolling.com/latest-polls