imo they think with their heart in a lot of cases and can't separate fact from the story they got told. the left leaning friends I have are wrapped up in one of these narratives and have a bit of ends justify the means attitude about it:

-orange man bad, fascist, Hitler must be stopped
-they honestly believe they are standing up for a marginalized group
-save the climate, save the planet

All rational talk of economics, math, authoritarianism, inflation, can't navigate to their heart