This is just the latest Pennsylvania poll to show Biden with an advantage. A mid-July Fox News poll put Biden's margin at 11 points.
What's the point: Trump won the 2016 election in large part because he was able to break through the big "blue" wall in Michigan, Pennsylvania and Wisconsin. He did so on the backs of White voters, and in particular White voters without a college degree. This led to those infamous memes of reporters seeking out voters in diners across America.
But today, Biden leads Trump in these Great Lake (or Rust Belt) battlegrounds because he's eating into Trump's margins among those very groups. These gains have big implications for the electoral college because they suggest Biden's easiest path to victory may be through these three states.
Biden has clear leads in an average of the last three CNN approved polls in the states of Michigan, Pennsylvania and Wisconsin. On average, Biden is up by 9 points in Michigan, 11 points in Pennsylvania and 10 points in Wisconsin.
Biden's upward trajectory is because of vast improvements among White voters in a comparison of Biden's standing in each poll to how Clinton did with them in an average of post-election estimates from the Cooperative Congressional Election Study and Center for American Progress.
Post-election estimates aren't the most ideal comparison to pre-election polling, which would be accurate pre-election polling (something missing from these states in 2016). Like any poll (or poll average), these post-election estimates are subject to error.
Still, the size of Biden's rise over Clinton in these states is clear enough that it's well outside the range of any statistical anomaly.
Michigan: Trump leads by an average of 3 points among White voters. Four years ago, Trump won amongst these voters by 15 points.
Pennsylvania: Biden is ahead by 3 points with White voters. In 2016, Trump won them by 15 points.
Wisconsin: Biden's up by 6 points with White voters. Last election, Trump took them by 7 points.
The key takeaway here isn't the exact shift in each state (which is subject to a margin of error), but that what we're seeing nationally in regards to White voters is occurring in the key Rust Belt states as well. Using the method nationally, Biden's improved from Clinton's 15-point loss to a mere 3-point deficit against Trump in the latest live interview polls. (This is quite similar to the movement seen using pre-election polls as our 2016 comparison point, which also shows a double-digit improvement for Biden.)
Obviously, the fact that Clinton underperformed her pre-election polls in these states should give us pause. Amazingly, however, these Rust Belt numbers among White voters are so good for Biden that he's in a considerably better position than even the final high quality pre-election polling that looked rosy for Clinton in each state.
View 2020 presidential election polling
We can drill down further to examine non-college educated White voters as well. Not ev