The reported poll was for registered voters. But they also applied a filter for what they called "definite voters." Now "definite voters" isn't a term of art pollsters usually use. But on the face of it it sounds like a really rigorous 'likely voter' screen. Because presumably people who are definitely going to vote are extremely likely. In any case, 'likely voter' screens almost always lean at least a bit Republican. That's in every cycle. And it's particularly the case in this cycle. But in this case, Newsweek's 'definite voters' were even more Dem-leaning than the 'registered voters.' Among the 'definite voters' the spread was Dems 50% to GOP 42%.
Now, the Newsweek poll looked at 'angry' voters and whether voter anger is really a driving force in this year's election; the verdict seemed to be no. As you can tell from the trend graph, there margin between the Ds and Rs has been closing for about a month, since right about the end of August. So either this Newsweek poll points to an intensification of that trend or its just an outlier from an already Dem-friendly poll. The fact that definite voters leans even more Democratic than registereds is very curious.