Clinton was a bad candidate, but keeping your share of the vote roughly constant while third parties gain a significant chunk is still a swing towards you. Clinton got a lower share of the vote in 92 than Dukakis in 88 but it was undeniably still a swing to the democrats.
Trump matching the margins of the Republican in 2008 and 2012 shows that his voters came out for him. Sure, technically it was a swing towards him, but it really shows that Clinton's base stayed home or voted third party. The 2020 candidate, most likely won't have the political baggage of Secretary Clinton, and even if they only get half of the third party votes back Trump still won't win these states.
I would say the same thing about the places where Trump performed horribly for a Republican, and the third party vote caused his vote share to collapse while Hillary performed similar to Obama, so the vote looked closer. Did places in Utah swing towards Hillary? Yes, but the 2020 nominee damn sure isn't winning there in 2020 because the closer margin had nothing to do with the Democrat and everything to do with the other side. Same applies in the states I mentioned in the original post. Trump made no inroads in the close states he lost to Hillary.
