See, “White” isn’t a race; it’s the default. It’s the way God made People. It’s how He made Adam and Eve, the first People, that is, White People.
White = People.
Race/racial refers to those who aren’t quite People. And no matter how much they wish or strive, they never will be. Get it?
Come back later for a lecture on how Evolution is Just a Theory (like Gravity).
You’re welcome. 
None of those explanations were attempting to explain that. Betting lines move due to market forces and are a reflection of all publicly available information.
My post was an attempt to explain how to interpret betting lines and to answer the following question:
The answer was that it wasn’t actually a huge move. One day the book maker (Jackknifed_Juggernaut doesn’t specify which) said Biden had a 62.6% chance to win. A few days later the same (presumably) book maker said Biden had 58.3% chance. Without knowing which book maker, a quick glance at RCP’s betting odds page tells me that if we looked today we’d see Biden’s chances somewhere between the first two data points.
It’s just noise, and not a huge shift that requires an explantation.
I really question this guy’s logic.
“The key to the November election is the primaries,” Norpoth said, adding Trump won Republican primaries quite easily while presumptive Democratic presidential nominee Joe Biden had difficulty winning delegates. “On balance, a stronger performance in primaries gives Donald Trump the edge in November.”
Well, dub, of course Trump had an easier time winning his party’s primaries. He’s an incumbent running for a second term.
Norpoth cited Biden’s fourth-place finish in the Iowa caucus and his fifth-place finish in the New Hampshire primary as among his reasons for his forecast.
“The terrain of presidential contests is littered with nominees who saw a poll lead in the spring turn to dust in the fall,” Norpoth told Mediaite . "The list is long and discouraging for early front runners.
This is more an observation on how Biden overtook Sanders. It really says nothing about Biden’s chances against Trump.
Norpoth seems to be making predictions about events which have already happened. He strikes me as a guy who made one lucky guess - that Trump would unexpectedly beat Clinton in 2016 - and now sees himself as an expert.
Sure, I get that. I’m just curious, because implicit in the question, I think, is why the book maker’s odds have changed (if only somewhat) while other predictors apparently haven’t. What are these betting markets? Who’s doing the betting, etc.
My understanding is the movement of the betting lines is driven by how people are placing bets.
In one sense, it’s a market force. But it should be remembered, it’s a self-selected force. The people who are placing bets are not necessarily reflective of the electorate. The number of people who place bets with bookies is around two to three percent of the population. The number of people who vote in presidential elections is around fifty to fifty-five percent.
The book maker’s odds changed (slightly) due to market forces (there was an uptick in the amount being wagered on Trump relative to Biden with the current line), and have likely already changed in the other direction. The most likely explanation for this is noise.
That’s a little worrying, but I look at polling averages. If I saw several polls like this, then I’d actually be worried.
Not unlike the stock market, amirite? 
I read his website and it really boils down to incumbency. If the incumbent party has held the presidency one term, they are hard to beat. If they’ve held it two or more terms, they have trouble winning.
As far as his “record”, it is not that impressive. The predictions before 1996 were made after the fact to test his model. A model based on those years! If it didn’t do well, it would have been discarded.
The primary turnout is supposed to reflect enthusiasm but really just strengthens the incumbency because they typically don’t have serious opposition.
In addition to what others said, his prediction is based almost entirely on the result of the New Hampshire primary. If ever there was a year where that is misleading, this is it.
You might be surprised. Here’s a article by someone who has done many focus groups of women who voted for Trump. Many are now having second thoughts.
Here’s the key quote regarding the riots:
“They don’t see Trump as someone who can protect them from the chaos—they think he’s the source of it.“
In general, white men with extra money. More Trumpist than the overall public. Bear that in mind.
I don’t know that I agree with the professor’s methodology, but I think I can explain the reasoning that you seem to be groping for.
Entirely setting aside the advantage of incumbency …
Candidates who dominate their party’s primaries pole to pole evidently have a lot of enthusiasts among that party’s voters. Conversely candidates who eventually win a long slow war of attrition in their party’s primaries evidently are the second choice (at best) of many of that party’s voters.
In the current geographically polarized = segregated environment plus the winner-per-state-takes-all EC system, what actually decides presidential elections is turnout. The majority of the electorate doesn’t bother to vote. That means it’s far easier and more productive to get one more lazy bastard of your own party off the couch and into the booth than it is to convert somebody of the other party to your own.
Said another way every American already knows which party they prefer. The big question between now and Nov 20 is which of those people bothers to cast a ballot1. Doubly so in the dozen-ish swing states and quadruply so in the one or two mongo swing states. THAT disparity in turnout is what determines who wins the EC.
The quintessential Bernie Bros demonstrated this in force in 2016 by choosing to sit out the race rather than hold their noses and vote for Clinton. And thereby handed it to Trump by default.
That difference in enthusiasm is what the professor is measuring. Which difference he posits translates directly into turnout in Nov which in turn translates into EC wins.
As to this particular election …
I’ve said in other threads that I don’t actually fancy Biden’s chances this Fall even though I certainly prefer the D party in general and Biden over Trump in particular.
One thing Trump has in spades is enthusiastic supporters. And the more he puts out apocalyptic advertising claiming Biden will crash the stock market, open the borders, let thugs rape your daughters, make America look weak, gut the DoD, or simply fall asleep, the more the marginally enthused R-leaning voter can find some pet cause (read “fear”) to rally behind. All Trump’s ads are get-out-the-vote ads. He’s already assumed the sale on which party you root for. The fact the ads are fact-free appeals to emotion is a feature, not a bug.
Conversely, Biden is a solid politician of the pre-twitter era. Lots of left-leaning voters (and not merely Bernie Bros) are lukewarm about Biden as an individual. Do they prefer him to Trump? Probably 90+% do.
But where are the effective get-out-the-vote ads for Biden? And how effective will they be when he’s got lukewarm support from a slothful, disenchanted, and resentful traditional D base and lukewarm support from the energized far-left youth wing, many of whom see him as yester-decade’s news pushing the kinder-gentler version of the same old wealthy elite line?
Intellectually these disenchanted Ds understand that abstaining helps Trump. But actually bothering to vote is mostly an emotional decision, especially for younger people. And conjuring strong emotion is not Biden’s strong suit as a person. Nor is it his legacy as shown through this primary season, such as it was in 2020 due to COVID.
How does that jive with the fact that turnout in the Democratic primaries have been WAY up this year? And especially in state were Biden blew out Sanders? News just came out from Georgia (where I live) that turnout for this years Democratic primary shattered all previous records. Now part of that may be an big increase of mail in absentee ballots, but that was 49% of the voters.
Like I hear this no enthusiasm for Biden stuff, but then how is he driving all these primary turnout numbers?
That has a great nugget in it: " Norpoth said if Trump is able to refrain from commenting or tweeting about political opponents and instead focus on the continued economic recovery from the COVID-19 pandemic, he stands a good chance of winning a second term."
This isn’t hard to figure out.
Betting lines are about where the money goes. They are not predictive, nor are they meant to be; they are designed that about half of the wagers win and half of the wagers lose and they keep all the vig with little risk.
What happened is that a bunch of people saw Trump getting long odds so they wanted to bet the longshot. Enough people do that and the line has to adjust to encourage more money going on the favorite.
Look at the polling aggregate at fivethirtyeight: On June 16th Biden’s national spread went past nine points for the first time. Since then the spread has always been between 8.9 and 9.6. It is currently at 9.6 which matches the highest it has been.
Gamblers emotionally backing a longshot in the hopes of a big payday is a lot more likely explanation than some hidden force that the polling has not detected.
I kind of suspect that polls at this point aren’t quite as inaccurate as the Old Farmer’s Almanac at predicting the weather in November, but close. Or if you prefer, think of it as a real meteorologist-produced weather forecast. Really accurate up close, but as the time horizon gets larger, the number of variables and uncertainty blows up, and the accuracy of the forecast goes down.
Except they’re not. Only one time in an incumbent election has an incumbent overturned a deficit like this in July polling. That was, of course, Dewey v. Truman. And even there Dewey never polled over 50% like Biden is pretty consistently doing now.
July is actually a pretty accurate moment typically since it’s after the primaries but before the conventions. For example in 2016 at this point Clinton’s average lead was about 4.5% - she won by about 2%.
Now maybe polls are fatally flawed, suddenly (even though they were decent in 2016 and quite good in 2018). But that’s certainly not a 50/50 bet.
I think they’re more accurate than that. 538 did a survey of past poll predictions taken four months before the election and the average difference between the predicted outcome and the actual outcome was seven percent. Biden currently has a lead of above nine percent.
I don’t know. But I’d be concerned that a significant number of Republicans will “hold their nose” and vote for Trump simply because they won’t vote Democrat. And if enough moderates and Democrats aren’t excited enough by Biden to get out and vote, Trump might win.