538 Model Megathread

[pbrower2a]

Other than AZ, it looks ok ...

I'd give AZ to Trump in a close race, because the state's laws that will block Latinos from voting.

Not with the Obama Administration doing everything possible to protect the voting rights of blacks, Latinos, and First Peoples in Arizona. Nobody is going to get a chance to do anything squirrely with the vote in Arizona.

More troubling to Donald Trump could be that many white Anglo Arizonans have a Mexican-American in the family... and there could be many non-Latinos deciding that Trump's ugly statements about Mexican-Americans badly fit the reality of an in-law, co-worker, etc.    

[pbrower2a]

Map showing likelihood of wins for Clinton and Trump, Johnson considered

chance of
win          sat

99%+       9
95-98.9    8
90-94.9    7
80-89.9    6
70-79.9    5
60-69.9    4
55-59.9    3
52-54.9    2

[pbrower2a]

Making any definitive prediction before the conventions and debates is foolish

Things will change.  So what does it mean that at this point Minnesota has an 85.7% of winning Minnesota and Donald Trump has a 14.0% of winning Minnesota? For now, Nate Silver has made computer estimates of probability of Clinton, Johnson (practically nil), and Trump winning Minnesota.  Trump shows about 2800 results in which he wins, and Clinton shows about 17200 chances of winning Minnesota. Everything can go right for Donald Trump and he could get lucky and win Minnesota. But most likely the calendar runs out before Trump and the GOP has a chance to win the state. Maybe Donald Trump has a rally or two and they prove flops. He has then lost time better used elsewhere. Hillary Clinton plays a nickel defense that allows Donald Trump to lose slowly as a 9% lead shrinks to 5% on Election Day. That's a losing proposition for Donald Trump. Or Donald Trump quits buying ads and making appearances in Minnesota. An 85.7% chance for Clinton becomes a 90% chance, then a 94% chance, then a 96.7% chance, then a 97.2% chance, then effectively no chance in late October or early November. People have no surprise when the networks call Minnesota quickly on Election Night. After all, it is Minnesota, which hadn't gone for a Republican nominee since it was the 49th-best state for Richard Nixon in 1972. Minnesota has a high floor for Republicans in one of their better years (about 49%) and a low ceiling (about 58%) for Democrats.

Can things go so right that Republicans have a chance in Minnesota? Sure. The economy can go into a sudden and severe tailspin, ISIS can suddenly take over Iraq, Hillary Clinton can be caught in a sex scandal, a terrorist act might discredit an inattentive Obama administration... that all takes some imagination. In such a case, many other states swing toward Donald Trump. But the longer that time passes, the less likely such things can happen. Again, time runs out if none of those things happen, and the current estimate that Nate Silver has has gone from an 85.7% chance to a 99.9+% chance of Hillary Clinton winning Minnesota. An 8% lead in late June? That can disintegrate. It can also solidify, and it is practically impossible for an 8% lead to disintegrate in late October and early November.

Now let's try a state that is closer to an even chance of going one way or the other.  Hillary Clinton has about a 41% chance of winning Georgia and Donald Trump has about a 59% chance. That's nearly a coin toss. An 8% lead can disintegrate in 4 months. Obviously, Hillary Clinton does not win Georgia without winning North Carolina (similar demographics) and winning Florida decisively (which a recent poll suggests). Some things are possible. No, not a return to the political realities of the time when Jimmy Carter was Governor!

Georgia suburbs have been unusually strong, for American suburbs, in voting Republican in recent years. If those suburbs start voting like the suburbs of St. Louis, then the Republicans' chance of winning Georgia get wiped out. The white vote in Georgia went heavily R in the last two Presidential elections, perhaps out of distrust of you-know-who. You-know-who isn't on the ballot this time. Let the rural white vote become more like the rural white vote of Kentucky, and Democrats win Georgia. Georgia has a huge presence of active military personnel, and they pay attention to foreign policy. Bad foreign policy can get soldiers killed. Let Hillary Clinton seem too dovish on foreign policy, and she loses Georgia decisively. But let Donald Trump seem too reckless, and many soldiers and their spouses decide to vote for Hillary Clinton.

So guess what happens if Donald Trump tries to force a win in Michigan, which he now has about one chance in 11 of winning and maybe one chance in 33 in early October. He ends up neglecting states like Missouri, Georgia, Arizona, and maybe Indiana that really are in play. He loses a couple of those.  

I'm not saying that any of these scenarios play out. They can, and if they do they can change the reality of the Presidential race more decisively than the winner running out the clock in a political equivalent of the nickel defense.  The one ahead yields ground for time, but not enough to allow a victory to the other side. The team up 24-3 at the half can afford to let the team behind make some ground gains -- but any attempt at a long pass results in an interception that makes things even worse for the team behind. The nickel defense gives a team decidedly behind the choice of how to lose the game.

Hillary Clinton is in the position in which she can play a cautious game and win. Donald Trump may have to make desperate gambles that have a slight chance of winning or can make him lose the Electoral college 450-88 or so.          

[pbrower2a]

Map showing likelihood of wins for Clinton and Trump, Johnson considered

Note: this is likelihood and not margin. Margin may be related to likelihood at this stage.

chance of
win          sat

99%+       9
95-98.9    8
90-94.9    7
80-89.9    6
70-79.9    5
60-69.9    4
55-59.9    3
52-54.9    2

[pbrower2a]

Making any definitive prediction before the conventions and debates is foolish

An 80% chance is not exactly definitive.

Of course. In a best-of-seven playoff series, a team up 3-0 can still lose (assuming that the teams are really equal) the series. The chance of such is 1 in 16, or 6.25% of the time.

Four months remain, and as much can go wrong for Hillary Clinton as it can for Donald Trump. At this stage, if nothing happens except the passing of days, then Hillary Clinton wins. If the same margins existed a month from now, then Hillary Clinton's chances for winning rise while nothing big happens.

Silver's model cannot predict a collapse. It can only show it as it happens.  

[pbrower2a]

Here's the old forecast from 2012. In particular, I miss the explicit "tipping point state" probabilities this time.

The Presidential election of 2012 was easy to model because

(1) it was not an open-seat election
(2) the President was predictable enough and perceived to be neither a spectacular success nor failure
(3) the Parties have little ideological overlap
(4) the States were sharply polarized in their partisan affiliation, and this was stable
(5) there were no new causes and there was no pervasive change in cultural patterns


So look at those factors. (1) An open-seat election usually hinges upon who wins contested primaries and caucuses, and it is often difficult to predict who will win that. Incumbents rarely lose nominating processes, so that leaves  the incumbent in an election usually his to lose.  That does not apply this time, of course. 22nd Amendment.

(2) History will almost certainly rate Barack Obama as an above-average President, even if most people saw him as a mixture of successes and disappointments. He did not expand his coalition as did FDR, JFK, or Reagan. But neither did he make many mistakes. "General Motors is alive and Osama bin Laden is dead" became the unofficial slogan of Democrats in 2012.

OK. Putting an end to the most dangerous economic meltdown in nearly eighty years and whacking the worst anti-American terrorist ever while avoiding scandals and military or diplomatic disasters is one way to get re-elected even if one loses about 20 states by 10% or more in the previous election. Barack Obama should have been re-elected and was.

(3) The 2010 election knocked out the conservative wing of the Democratic Party in the House of Representatives, and the Republican Party has nothing close to a liberal. Ideological choices between candidates are rather stark. Such makes individual choices easy

(4) Barack Obama winning Indiana in 2008 was something of a freak, something that happens when a state has a large industry (recreational vehicles)  whose market can be hit hard by a combination of an economic downturn, a credit crunch, and high gasoline prices, all of which hit in 2008. That is the only big swing in a state that Barack Obama won. The shift of the Deep and Mountain South from D to R between 1976 and 2008 was basically complete, and it now looks irreversible.

Barack Obama did not depend upon freakish conditions that could evaporate quickly to win.

(5) Tea Party? That's the closest thing to social change. There was no great new religious revival to create a new right-wing ascendancy and no leftish populist movement appearing from seemingly nowhere.

So I could come up with a model. First, recognize that seventeen states and the District of Columbia had not voted for any Republican nominee after 1988 and that there was no marked Republican drift in any of them. That's 243 of the 270 electoral votes that one needs for winning the Presidency, nearly 90% of the needed vote. Second, figure that three states had voted  only once for a Republican nominee for President in the same time, and showed no sign of going Republican this time. That's up to 258. That means that either Virginia, Ohio, Florida, or the combination of Colorado and Nevada would win the election/ Some other states?

Obama wasn't going to win Missouri without winning either Ohio or Virginia; he wasn't going to win Indiana without also winning Ohio; he wasn't going to win Arizona without also winning Colorado and Nevada; he wasn't going to win North Carolina without also winning Virginia; he wasn't going to win Georgia without winning Florida, North Carolina, and of course Virginia.  He also wasn't going to win Colorado without also winning Nevada.

So the 2012 election boiled down to four states -- Colorado, Florida, Ohio, and Virginia, any of which would decide the election. Those states are different enough and separated enough that there is no way to make an appeal that could resonate in all four of those states without
shifting America on the whole.

Treat winning any of the four states as  what statisticians call independent events (coin tosses and throws of a die are independent events), and my crude model held that President Obama had one chance in sixteen of losing if each of the states was a 50-50 proposition. I saw President Obama having a 93.75% chance of winning with all four of those states as 50-50 propositions.

We know how the election turned out. Obama was as successful as Mitt Romney had to be lucky in winning all four states.   
 

So what is different this time?

(1) it was not an open-seat election This one is!
(2) the President was predictable enough and perceived to be neither a spectacular success nor failure has done nothing to hurt any Democrat running to be his successor
(3) the Parties have little ideological overlap (and still do)
(4) the States were  remain sharply polarized in their partisan affiliation, and this was is  stable
(5) there were no new causes and there was no pervasive change in cultural patterns(still true)

Donald Trump, having no experience as an elected public official or as a senior military officer , will be the first nominee for President for one of the two main Parties since George H W Bush  who has never won a statewide office (and George H W Bush showed the effect in 1992 and Ford showed the effect in 1976) and has not been a senior officer or a winner of any public office since Hoover in 1928 (Hoover at the least was a Cabinet secretary). If Americans really want a non-politician, then Donald Trump is the choice. Hillary Clinton is trying to run as a "steady hand", "stay-the-course" type.

This is Hillary Clinton's election to lose and potentially Donald Trump's election to lose catastrophically badly.  Should Donald Trump win, he wins on Hillary Clinton's failure to campaign effectively.

Hillary Clinton has more political experience, and it is apparent that she has learned much by being a First Lady. She is linked to the most successful aspects of the Obama Administration (foreign policy) and makes few gaffes on public policy.

At this point, Donald Trump is behind Mitt Romney in consolidating likely votes for himself. Mitt Romney still lost.