Gist is that the longer your commute, the less likely you are to care about politics. Vote, have a voice, be involved.
The discussion blamed the correlation on stress. A stressful commute leaves people too tired to think about their world. They also said that the effect was more dramatic on lower income levels... a poor person with a long commute was very unlikely to be politically involved. A wealthy person with a long commute was actually more likely, probably because they can buy stuff when they get home to help them de-stress.
That sounded like a pretty screwed up theory to me, sounds like they were grasping at an explanation.
I've written before about isolationism and how I became much more politically motivated (and a bit more liberal) when I got to live in a lower-income area. I was exposed to different things.
I would think a commute would have the same effect. If you're wealthy, your commute probably takes you through lower income areas and you either want to make things better for them, or protect what you have.
If you're poor, you a long commute might take you out to more affluent areas. Just like pictures of skinny people do not help motivate dieters, being around rich people does not help the poor. It just makes everyone feel defeated. Remember "Bowling for Columbine", when he examined how long that woman had to ride a bus to get out to a mall to make fudge for rich people? She was away from her kid for the vast majority of the day... didn't excuse his behavior, but it was a shocking look at a case where everyone was asking "Where is the mother?"
So much about our politics could be fixed by listening to each other a little bit, living around each other, getting out of our little isolated boxes.