Here is my weekly update on the 2020 elections, based on State rather than national polling in the past 30 days, since that directly reflects what is likely to happen in the Electoral College. Remember that polls are really only nowcasts, not forecasts. They are snapshots of the present; there is no guarantee they will be identical or nearly identical in early November.
Let’s begin with Trump’s approval. After several weeks of improvement, this week Trump’s approval eroded very slightly – but remains right in its normal range for the past 3 1/2 years:

It is safe to say that Trump’s post-convention, “law and order” bounce has plateaued (note there have not been any big BLM demonstrations in the past week that have produced pictures of burned-out businesses).
In any event, here is the updated map through September 5. To refresh, here is how it works:
– States where the race is closer than 3% are shown as toss-ups.
– States where the range is between 3% to 5% are light colors.
– States where the range is between 5% and 10% are medium colors.
– States where the candidate is leading by 10% plus are dark colors.

The only changes are that Nevada moved back from “likely” to “lean” Biden, while Arizona improved from “lean” to “likely.” Maine also improved to solid Biden, while New Hampshire declined to “likely” Biden. With the exception of Arizona, all of these have been on the basis of skimpy polling. I continued to be surprised that so little polling attention has been paid to Nevada.
While Biden’s “solid” plus “likely” Electoral College votes have declined from their peak of 302 six weeks ago, this week they improved from 279 to 284. Absent a *legitimate* “October surprise,” i.e., nothing that has been telegraphed in bright shining neon lights by the likes of William Barr, or a dramatic further explosion of social unrest, Trump is going to need to resort to thoroughgoing vote shenanigans to avoid a likely defeat. I believe the public’s perception of both the economy and Trump’s handling of the pandemic have congealed. I do expect some further incremental improvement in Trump’s position as voters who were leaning GOP “come home.”
There have also been several changes in the Senate map this week, in opposite directions, all based on light polling:

Iowa reverted back to toss-up from “lean Democrat.” New Mexico declined to “likely Democrat,” and Maine to “lean Democrat.” By contrast, Montana moved from “likely” to “lean GOP.”
At current polling, if Democrats win all those seats rated “solid” and “likely,” they will have 49 Senate seats; 50 with “lean Democrat” Maine; up to 54 with the “toss-ups,” and 56 if they were to capture the 2 “lean GOP” seats.
Early signs the bottom might be falling out on Trump in 2020, just as it did for McCain this same week in 2008
via @BostonGlobe – September 17
Since 2000, presidential elections have been won in the margins. Some wins were bigger than others. But compared to the previous century, this two-decade period of competitive elections is a testament to how polarized the country has become.
But there is one exception to the recent rule: Barack Obama’s landslide victory in 2008. In November, Obama stomped all over Republican John McCain. Obama took 68 percent of Electoral College votes by winning states like Indiana and Virginia that no Democrat had won since 1964.
For most of that year, the 2008 presidential campaign didn’t feel like a landslide at all. Indeed, in early September national polling from reputable outlets like the Associated Press, CBS News, and ABC News all had McCain ahead of Obama. A USA Today/Gallup poll had McCain up 10 points on Labor Day weekend.
But shortly after, the bottom fell out on McCain.
It was painfully obvious and he never recovered.
In the last 24 hours, the 2020 presidential race began to feel a lot 2008. A series of new polls imply the bottom might be falling out on Republicans again, especially for President Trump. …
The latest two polls out in Minnesota show Trump down 9 percentage points and 16 percentage points, respectively. In pivotal Wisconsin, a CNN poll found Biden doubling his lead there to 10 points, which, if true, would put both Midwestern states out of reach. Even in the only electoral vote Trump won in New England, Maine’s Second Congressional District has flipped to Biden, according to a Quinnipiac Poll out Wednesday that showed Trump down 9 percentage points there.
It is getting so bad that the same polling outfit showed that Trump was only winning rock-ribbed Republican South Carolina by 6 percentage points. If that poll proves to be correct then it suggests that other places that are less Republican, like Georgia, are probably headed Biden’s way for a landslide in November.
Thursday morning, after yet another poll showed Biden winning in Arizona, the nonpartisan and highly respected Cook Political Report shifted the state from a toss-up in the presidential race to leans Democrat. (Bill Clinton won Arizona in his 1996 reelection campaign, making him the only Democrat to win there since 1948.) …