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Trump is trying to grab some of Biden's most valuable supporters. Here's how.

Analysis: The president is distracting attention from COVID-19 and making a strong appeal to non-college-educated white voters who are key in battleground states.
Image: Presidential Candidate Joe Biden Holds Campaign Event In Pittsburgh
Joe Biden speaks during a campaign event at Mill 19 in Pittsburgh on Monday.Alex Wong / Getty Images

It's too soon to say whether last week's Republican convention made any dent in the polls. But it did make clear President Donald Trump's chief line of attack going forward: After months of drifting between calling Joe Biden senile or soft on China, Trump and Republicans have settled on recasting him as a "Trojan horse for the radical left" who would promote lawlessness and disorder, "abolish" the suburbs and crash stock markets.

It's an admission that Trump needs to distract attention from voters' top concern — COVID-19. And Trump's rhetorical fusillades against "Democrat-run cities" are a tell of a fall strategy heavy on pumping up his base from 2016: small-town, working-class white voters.

So far this summer, Biden has polled spectacularly well in suburbs — even historically GOP ones in the Sun Belt — thanks to his strength among college-educated white voters.

In an average of live interview polls taken in August, Biden led Trump among that group by 56 percent to 39 percent, compared to Hillary Clinton's 50 percent-to-38 percent lead in final 2016 polls. But he's also polling impressively among whites without college degrees: August polls showed Biden trailing Trump by 35 percent to 57 percent among that group, a narrower margin than Clinton's 30 percent-to-58 percent deficit in 2016.

However, against the backdrop of civil unrest in Kenosha, Wisconsin, and Portland, Oregon, Biden's support in the latter group is more fragile. Although Biden, a Catholic from Scranton, Pennsylvania, has long been considered something of a patron saint of blue-collar Democrats, blue-collar white voters tend to pay less attention to politics day to day than others and live in pro-Trump settings where the local news and information ecosystem, driven by Facebook and other social media sites, is much friendlier to Trump's view of the world.

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It's in those places where Trump's onslaught of attacks, including false accusations that Biden wants to "defund the police," stands the best chance of resonating and where Biden will need to claw to hang on to the voters who currently find him plainly acceptable.

Biden's lead in swing states is attributable to voters like Ralph Perkins, 89, a retired mining engineer from Canonsburg, Pennsylvania, 20 miles southwest of Pittsburgh. The New York Times reported last month that "the one thing could lead him to vote a second time for Mr. Trump would be if Mr. Biden supported defunding the police. 'Biden, I think he's very much superior to Trump,' Mr. Perkins said. 'Do I think he's perfect? I'm not head over heels for him, but I think he's fine.'"

In addition to trying to pry voters like Perkins loose, Trump hopes his "law and order" message will turn up more voters like Mike Mazza Jr., 55, a carpenter who lives in Carbondale, Pennsylvania, in the opposite corner of the state. Mazza told The Philadelphia Inquirer last month that after having sat out 2016, he believes Democrats have gone too far left and that "I'm just sorry I didn't wake up soon enough to vote for [Trump] the first time."

Biden doesn't have much risk with that type of voter in Sun Belt states. In 2016, whites without college degrees made up just 34 percent of all voters in Texas, and Trump won them by 78 percent to 18 percent, according to an NBC News analysis of census and voting data. In Georgia, they made up just 38 percent of all voters, and Trump won them by a whopping 82 percent to 14 percent.

By contrast, Trump's opportunity to grow his vote and get back into contention lies with blue-collar white voters in Great Lakes battleground states. In Minnesota, whites without degrees made up 54 percent of all 2016 voters, and Trump won them by a more modest 58 percent to 34 percent. In Wisconsin, whites without degrees made up a massive 60 percent of the vote, and Trump carried them by 58 percent to 36 percent.

As Labor Day approaches, Biden remains very much on offense, but he is entering a phase when he'll need to play "prevent defense" against Trump's increasingly bellicose attacks. Without the kind of door-to-door field effort the Trump campaign has proven willing to undertake, Biden will likely have no choice but to air ads in swing states forcefully confronting Trump's assertions about riots and police funding.

On the current trajectory, Biden has outstanding chances to flip traditionally GOP-leaning states like Arizona and Florida and perhaps even Georgia and Texas. But if he were to fail to counter Trump's appeals to working-class white voters, Minnesota and Wisconsin could turn into the next Iowa and Ohio.