A national poll of likely voters by Emerson College shows Joe Biden losing ground to Donald Trump following the Republican National Convention. Biden still leads. From Emerson:

Key Takeaways
  • Trump’s approval at highest point since 2016

  • General election gap tightening– Biden now leads by 2

  • Trump continues to lose ground with voters 65 and older

So is this an outlier? Jim Geraghty, writing at National Review, puts it this way:

Nate Silver’s FiveThirtyEight gives Emerson an “A-” grade, so the “this group of pollsters don’t know what they’re doing” probably is not going to fly.