Harris, however, is now in a much stronger position in the trio of must-win states. In Michigan, Pennsylvania, and Wisconsin, Harris now leads Trump by four-point margins each (50% to 46%) among likely voters.

In the latest polling, Harris showed strong results among the groups she’ll need to win over to defeat Trump in the November general election.

Across the three states, Harris held a 20-point lead over Trump (58% to 38%) with women and a 15-point advantage with voters aged 18 to 29 (56% to 41%). Harris led among suburban voters by a 10-point margin (53% to 43%), and she even retained much of Biden’s strength with seniors, leading among the latter group by 13 points (55% to 42%) across the three states.

The latest survey is significant because both Harris’s and Trump’s campaign strategies are rooted in appealing to voters in these battleground states.

Pennsylvania is the biggest electoral prize of the group, with 19 electoral votes. Many Democrats wanted Harris to tap the state’s popular governor, Josh Shapiro, as her running mate. But earlier this week, she opted for Minnesota Gov. Tim Walz, a former congressman who, for 12 years, represented a conservative-leaning district but has compiled a progressive record as the state’s governor.

Democrats believe Walz will still be an asset to Harris in Pennsylvania but also add support in the Midwestern battlegrounds of Michigan (15 electoral votes) and Wisconsin (10 electoral votes).

For Trump, the July selection of Republican Ohio Sen. JD Vance as his running mate was supposed to be a nod to his conservative base in a contest that, at the time, was moving increasingly in his favor.

But Harris’ entrance into the presidential race completely reset the dynamics. Vance has so far struggled to appeal to the suburban swing voters who were once on the fence but who now appear to see a viable alternative in the vice president.

Harris is poised to enter the Democratic National Convention on August 19 as the slight favorite in many of the closest swing states. Should Harris receive an added polling bump after the convention, it would surely put even more pressure on Trump to reorient his campaign in advance of the September 10 debate between the two candidates.