I don’t see either doing better than Nadar in 2000, who was far more known and more popular than Johnson and Stein are now, combined. Nadar received 2.74% of the vote in 2000, and 3.75% in total voted 3rd party. We haven’t come close to those percentages since.
I agree with Ref I expect the third party’s to get about 7ish percent of the vote. It’s not because they are popular but because folks will vote for them rather than Trump or Hillary.
The way I see things is a bit flipped from Ref is claiming. I think Hillary is low 40s... Third party gets about 7ish percent and Trump gets upper 40s. Only way you wind up with a different play is if Trump voters stay home and I just fdont see that happening.
Both major candidates are under water in their approval numbers, which has never happened. Some of that surplus negative vote will definitely go to third parties.