My personal experience is that, in general, Gen X'ers (like Buttigieg) and Millennials tend on the margin to be more pro-rail than the prior generations. Part of it has to do with what you experienced.
If you're like me, born in the New York suburbs in 1975, you have no memory of the bad days of the late 1960's in passenger rail, when, with a few exceptions, the big rails were either bankrupt (PC, etc.) or actively trying to discourage passenger ridership with lousy service (SP, for example.) My earliest memories of Amtrak, for instance, involve Amfleets and AEM7s clipping along on the NEC.
By the time I became aware of what was going on around me the Interstate Highway system had been complete for a couple decades, if not more. Roads around urban areas were congested and increasingly potholed. And there was an increasing realization that things like the Cross-Bronx Expressway or the Fitzgerald Expressway were terrible for the urban fabric.
At the same time, the de-regulation of the airlines, the resulting focus on lower fares and demise of carriers like Eastern and PanAm meant that the overall air travel experience got worse year by year-- to the point, today, where people would rather take a bus than fly if the time penalty isn't too much.
It's a completely different mindset than that of someone who was born in, say, 1950-- who came of age in the 1960's, when superhighways and jet planes were new and the average passenger train was elderly heavyweight equipment whose best days were 20+ years in the past.
