What is the probability that most 2020 GE polls will include > 2 candidates?

[Mr. Morden]

In the 2016 campaign, most of the major pollsters included Gary Johnson and/or Jill Stein as options in their polls, at least those polls conducted late in the race.  This was a break from recent campaign, as no 3rd party option was included in most major polls for the 2004, 2008, and 2012 races.

What about 2020?  What's the probability that most pollsters will include at least one third party option in their polls taken after the major party conventions?

Because one thing I'm wondering about is if, now that the precedent has been set that the Libertarian and Green nominees get included in polls, that precedent will continue into 2020 out of force of habit, even if there's little "organic" support for the candidates in question.  Will the media default to treating the Libertarian and Green parties more seriously than they did pre-2016, which could itself prompt voters to continue giving them a few % of the vote, as in 2016?

[History505]

In the 2016 campaign, most of the major pollsters included Gary Johnson and/or Jill Stein as options in their polls, at least those polls conducted late in the race.  This was a break from recent campaign, as no 3rd party option was included in most major polls for the 2004, 2008, and 2012 races.

What about 2020?  What's the probability that most pollsters will include at least one third party option in their polls taken after the major party conventions?

Because one thing I'm wondering about is if, now that the precedent has been set that the Libertarian and Green nominees get included in polls, that precedent will continue into 2020 out of force of habit, even if there's little "organic" support for the candidates in question.  Will the media default to treating the Libertarian and Green parties more seriously than they did pre-2016, which could itself prompt voters to continue giving them a few % of the vote, as in 2016?

A pretty high chance, although the thing I'm curious about is whether there will be another third party candidate to make it on the general election debate stage in the near future, since its been over two decades since the last with Ross Perot in 1992. Is there any potential third party candidate out there that could poll high enough to be given admission on the stage? Gary Johnson couldn't succeeded in that.

[SingingAnalyst]

Small. Most people are either pro-Trump or anti-Trump. The "market" for minor parties will be small in 2020, I predict.

[MarkD]

Early on the polls will include third party candidates, but if the polling indicates that no third party candidate is getting at least 1% then the pollsters will stop including them.

[America's Sweetheart ❤/𝕿𝖍𝖊 𝕭𝖔𝖔𝖙𝖞 𝖂𝖆𝖗𝖗𝖎𝖔𝖗]

Unless someone like Mark Cuban or Mike Bloomberg runs as an independent, fairly low.

[Mr. Morden]

Small. Most people are either pro-Trump or anti-Trump. The "market" for minor parties will be small in 2020, I predict.

Early on the polls will include third party candidates, but if the polling indicates that no third party candidate is getting at least 1% then the pollsters will stop including them.

Yeah, I’m not convinced it works in the way that either of you suggest.  You’re suggesting a kind of “bottom up” regime in which organic support for 3rd party candidates helps determine whether or not the 3rd party candidates get included as poll options.

I don’t think it works like that.  I think it’s much more “top down”, where media figures determine who is worthy of inclusion in the polls, and then their very inclusion in the polls can ultimately end up driving up their share of the vote.

I mean, first of all, I think it’s almost automatic that any 3rd party option is going to end up getting a few % in a poll if they’re listed as an option, even if that support ends up not being real.  There are a few % of voters who don’t like either party, and will express that in a poll.  This isn’t just unique to situations like 2016, where both major party candidates were extremely unpopular.  In the few 2012 polls that included Johnson and/or Stein, they still managed to get a few %.  E.g., in this poll from September 2012:

http://i2.cdn.turner.com/cnn/2012/images/10/01/rel11a.pdf

It was:

Obama 47%
Romney 43%
Johnson 4%
Stein 3%

So I don’t think it’s going to happen that if 3rd party choices are included in 2020 GE polls, that they’ll only be getting 0-1%.  That seems unlikely.

So then, the question is, why did the pollsters decide to include 3rd party candidates in most of the 2016 polls and only in a few cases in the 2012 polls?  I think it was largely a consequence of #NeverTrump GOP elites.  There were a slew of both Republican politicians and conservative media figures who said they wouldn’t back Trump in 2016.  So then the natural question becomes who are you going to support instead, and the Libertarian nominee, whoever that have been, naturally becomes part of the speculation, and I think that helped lead Johnson towards inclusion in the 2016 polls.

And here’s the thing: I’m not sure it’s going to be that different in 2020.  Yes, Republican *voters* are largely behind Trump, but are folks like Bill Kristol going to endorse him, or will they at least float the idea of going with another option?  If the latter, then we could be in for another round of 3rd party speculation.

Or alternatively, maybe the pollsters will now just keep including the Libertarian (and Green?) nominee as a poll option because the precedent has been set by 2016, and they’ll just continue it.  I really don’t think the choice to include them or not has much to do with whether they have any organic support among voters.