What on earth do you mean by “free and fair” elections?
Under an electoral framework derived from democratic principles, assuming¹ that the primary/caucus system remained and the US still operated within a presidential paradigm, basically anyone would have beaten Donald Trump. We are talking about a stupidly unpopular dude with absurd mannerisms. And while people knew this stuff in the reality that we inhabit, to a very large extent, Trump’s mannerisms are rational responses to the way the system works.² Having nutty policies that kind of appeal to some people in some states obviously makes some sense if you can ignore the people who it turns off because they live in irrelevant states. Similarly, acting outside the normative conventions attracts people like you who are just happy to see anti-establishment behaviours. This was rewarded because it was new, and it was new because the US doesn’t have a democratically derived electoral system.
However, we might also think that you’re criticising the primary process. This is a more tenuous claim to make. The best way to talk to the party faithful is different to the best way to talk to the electorate at large. As a result, it is not possible to see how the rival candidate will evolve when they switch to talking to the electorate. Hence, if you try to position yourself as the “candidate who will beat Trump” in the primaries, you choose a risky strategy that doesn’t mesh particularly well with spouting the kinds of things the party faithful like. This is especially true if, like Sanders, you are actually opposed to easy sells to Democrats like gun control. And, of course, if the primary process is the “electoral” aspect you’re criticising, Donald Trump still has nicely aligned demographic distribution.³ But there is also a further problem.
As I have noted, attacking the other party’s candidate is not something that primaries are particularly likely to reward. They are for the party faithful, so positive emotions/stances are more effective: be for something, not against something else. Yet, attacking primary rivals does make sense: criticising their person is more useful than criticising their visions all the same. As a consequence, we never really saw what exactly a concerted anti-Sanders effort from the Republicans would have looked like. In a “free and fair” system with primaries, Sanders would have had to deal with practically half of America being told and believing that he was an evil communist. Even with Trump’s interesting views on Russia, communism would surely have been a great ploy. After all, you can make the Chinese communists and thus get away with Putin-worship (not that I am suggesting Trump has a Putin shrine built in all his hotels in a “plant room”). And, as you can tell by the Russia thing, selling Cold-War narratives still works in the US.
Another complication is that in a generalised “free and fair” system, the institutions are less friendly to personality so policy matters more. This doesn’t have to be a substantial difference, but it exists. Which raises the questions of how attractive Sanders’ positions would actually have been. Sure Trump was against free trade on campaign, but he also showed signs of a President Business⁴ mentality. I suggest that the hypernormality⁵ of Trump would have come across much more clearly against someone like Sanders and, hence, Trump would have seemed much more, well, sane. That has an appeal.
So, what do you mean by “free and fair”? How wide ranging are the changes?
¹ These are large assumptions.
² Hell, the scandalous nature of Trump’s campaign gave it a certain dynamic energy, especially relative to Clinton’s, and the primary process had played out in a manner that gave Trump a certain momentum. It is possible to be a complete dickhead and even have anti-democratic scandals and be untouchable, but not if you’re also a prick… when you’re a prick you’ve got to have everyone believe you defy gravity to defy gravity.
³ Trump is not a “Black Swan”. Even if one ignorantly believes 30% is a very small chance (“big upset”) of winning, it doesn’t change that models which evaluated the possibility of “EC win and popular vote” defeat all thought this more likely for Trump than Clinton.
⁴ Yes, that’s a reference to the Lego Movie.
⁵ By which I mean, Trump seems extreme or abnormal only because he does more of what is normal. Normal Presidents Tweet… Trump tweets a lot. Normal Presidents have anti-immigration policies…. Trump wants a wall. Normal Presidents carry insiders with them… Trump’s practically President Nepotism. Normal Presidents value national security… Trump bans countries. Sanders’ rhetoric is actually more paradigm shifting.