If every third-party voter voted for either Trump or Clinton

[DPKdebator]

If everyone who didn't vote for Trump voted for Clinton:

324 - 214

If everyone who didn't vote for Clinton voted for Trump:

355 - 183

This map just goes to show how strongly the third-party voters affected the election, especially in the Southwest and Midwest. Obviously, not every third party voter would've voted the same way but is interesting to see how much a small swing (except for NM and UT, the most percentage increase a candidate would get is around 5-6%) affects the EC so greatly.

[BidenDuckworth2020]

Clinton would have also lost Virginia. She only got 49.75% of the vote.

[Klartext89]

Utah should be left out, there's no way that every McMullin voter would have gone for Clinton, whatever.

[○∙◄☻¥tπ[╪AV┼cVê└]

Is this at gunpoint? A large number of people didn't like either of them.

[publicunofficial]

Evan McMullin's greatest impact on the race was arguably not in Utah, but in Minnesota. Give even half of McMuffin's voters to Trump and he wins there.

[vote for pedro]

Utah should be left out, there's no way that every McMullin voter would have gone for Clinton, whatever.

Yeah, I find it more useful to look at the combined map - It's really just a list of states where the winner got less than 50% of the vote.  It doesn't necessarily mean they are ready to flip:

[DPKdebator]

Clinton would have also lost Virginia. She only got 49.75% of the vote.

There, it's fixed. I should've taken a closer look at VA, but I didn't read the <1% votes.

[AGA]

North Carolina should be flipped on the first map.

[Mr. Smith]

North Carolina should be flipped on the first map.

As should Nebraska CD-2.

[rob in cal]

  Was there any polling asking third party voters who their choice would have been between Trump and Clinton?

[MarkD]

Is this at gunpoint? A large number of people didn't like either of them.

Me, me, me, me!!

[vote for pedro]

If you really want to have fun with this concept, look at a year like 1992 where the only majority winners were DC and Arkansas.

Anywhere from 538-0 to 9-529.

[°Leprechaun]

Of course, all of this is useless idle speculation, albeit fun for some, no doubt.
IRV IRV IRV
Then it wouldn't be a "what if" scenario... (or approval voting which would have a similar if
not identical outcome).
Write it down 200 times, "I will support IRV". Plurality voting makes not sense to me.
It would be hard to "argue the opposite". The only reason to support it is to maintain
the status quo of "Democrat v Republican" which is a false dichotomy and hasn't seemed to be very effective. Those who support the status quo and think that everything is fine, undoubtedly are more likely to support plurality voting. What happened in Maine (the irv referendum) was a good thing.

[°Leprechaun]

Is this at gunpoint? A large number of people didn't like either of them.

Unfortunately a large number of people also feel that they have to support the "lesser of two evils", even though they don't.

[°Leprechaun]

By the way, Reagan in 1980 didn't win a majority of electoral votes in states where he won a majority and yet it was considered quite a landslide. Most people are not aware of this.

[Sorenroy]

Same concept as the OP, but with shading and Atlas colors:

[twenty42]

Except for Utah, those maps are probably the respective ceilings for both parties going into 2020.

[Wisconsin+17]

The surprising thing is that Ohio wasn't a swing state. That's a really bad sign for democrats going forward.

[Figueira]

Except for Utah, those maps are probably the respective ceilings for both parties going into 2020.

Not really.

[DPKdebator]

Except for Utah, those maps are probably the respective ceilings for both parties going into 2020.

Not really.

Except for Georgia in a landslide, that is probably the best the Democrats can do if you take away Utah. Realistically speaking, the map for Republicans is probably their ceiling (although DE, NJ, CT, and RI could flip in a landslide).

[bouncycorn]

It would've been better if a third party candidate would've actually won

[jimrtex]

Same concept as the OP, but with shading and Atlas colors:

An alternative would be to assume that the 3rd party vote would have gone 80%, or 70%, or 60% for the 2nd place candidate, or maybe 64:16:20; 56:24:20; or 48:32:20, where 20% represented the dropouts.