Sanders is a better candidate than Hillary Clinton, but a worse political figure in every way. He has imported many of the prominent Trumpist affectations into the Democratic party—the us-versus-other bluster, the magical policy proposals, the imperious rejection of norms, the vicious online army—and marshaled them under a slightly different socio-economic banner. He is Trumpism for the left.
If 2020 settles into a choice between Trump and Sanders, America will long for the halcyon days of 2016.
And there is no reason to think that 2024 will be better.
Donald Trump views the presidency as a possession and government as a publicly-funded mafia. There is no reason to think that he will be willing to let this valuable prize be passed on to some independent—sorry, “independent”—Republican, such as Ted Cruz or Josh Hawley. Instead, he will almost certainly attempt to transfer the nomination to a direct heir of Trumpism. Possibly even an IRL heir.
And Republicans will be down for it.