Noticed uptick in third party voting this cycle

[Mr. Morden]

Of course, part of it is that people are more likely to vote 3rd party when they know who the 3rd party candidates are, and this year Johnson and Stein got a lot more media attention than they did in 2012, and were even included as options in almost every major poll from about ~May or so onwards.

As for *why* the 3rd party candidates got more coverage this time....sure, it's because people didn't like the major party candidates very much.  But I actually think it's more on Trump than it is on Clinton.  The Republicans who were looking to find an alternative to the major party choices were heavily overrepresented among political/media elites, which lies in stark contrast to the Dems dissatisfied with Clinton.  There were plenty of current and former Republican members of Congress, for example, who refused to vote for Trump, who then publicly deliberated about who they might vote for instead.  This resulted in the media paying more attention to who the alternative choices might be.  Whereas the #NeverClinton Dems were just ordinary voters, not political elites.

So I actually wonder, if the GOP had nominated a more "normal" Republican like Rubio, then would Johnson and Stein have actually gotten that much coverage?  Would pollsters have included them as options in polls?

[Mr. Morden]

Yes, it's true that the fact that the third parties got more coverage is more on Trump than Clinton, but when election day actually came around third parties took more votes from typical dem constituencies than they did from typical rep constituencies. Disappointed republicans came home far more in the final weeks than disappointed democrats did.

I’d say it’s a bit more complicated than that.  Did the 3rd party candidates actually draw more support from Democrats than Republicans?  Well, the exit poll says it was about the same, though a tick more from Republicans than Dems:

12% of Independents voted 3rd party, if we believe the exit poll
4% of Republicans voted 3rd party, if we believe the exit poll
3% of Democrats voted 3rd party, if we believe the exit poll

Of course, party ID is fungible.  People might just not be calling themselves Democrats or Republicans when they vote 3rd party, even if they normally vote one of the two major parties.  But the national House exit poll also has 5% of respondents saying they wouldn’t have voted for president at all if Clinton and Trump were the only options (and presumably those folks make up the bulk of 3rd party voters), and the poll has 49% of this group voting for the Republican in their House race, compared to 41% for the Democrat.

But you’re right that the 3rd party vote skewed heavily towards the young.  If you look at some of the pre-election polling that dug into this question more deeply though (e.g., some of the Quinnipiac polling) it looked like the 3rd party support was being drawn more or less evenly from both parties, but the Republicans defecting to 3rd parties were more or less spread out evenly across all demographics, whereas the Democrats defecting to 3rd parties skewed very heavily towards the young.  Which means that the overall average age of 3rd party voters skewed pretty young.  That may be what happened in the election, though the exit poll frustratingly doesn’t give us all of the data points necessary to clear it up.