538: Americans’ Shift To The Suburbs Sped Up Last Year

[Skill and Chance]

I'm guessing this shift is being caused by older millennials (1980-1988) settling down and starting families?

This might be good news for Republicans in 2020. I believe that conservatives become politically active later in life compared to liberals and that this point usually starts with when they start settling down and have a family.

There isn't much evidence at all for this, or for theories that going to college makes people more liberal.  Birth year effects dominate age effects in determining political views, we just happen to be in a cycle where younger people are more liberal right now.  Surprisingly few people ever switch parties after age 25.

This is why I have been pretty steadfastly expecting a long Democratic trifecta between the mid 2020's and mid 2030's when Millennials reach peak voting power.

[Skill and Chance]

I'm guessing this shift is being caused by older millennials (1980-1988) settling down and starting families?

This might be good news for Republicans in 2020. I believe that conservatives become politically active later in life compared to liberals and that this point usually starts with when they start settling down and have a family.

There isn't much evidence at all for this, or for theories that going to college makes people more liberal.  Birth year effects dominate age effects in determining political views, we just happen to be in a cycle where younger people are more liberal right now.  Surprisingly few people ever switch parties after age 25.

This is why I have been pretty steadfastly expecting a long Democratic trifecta between the mid 2020's and mid 2030's when Millennials reach peak voting power.

This is generally true. Although you do have instances such as with the silent generation where a significant chunk of them switched to the GOP under Obama when they use to be a very Democratic generation. But yes, generational patterns are always the best indicator.

But given how close the 2016 results were, especially in the rust belt, any minor shift in voting habits even if it's for just one electoral cycle would have huge impacts for that election alone.

By 2030ish, Dems likely won't need the Rust Belt*, even for the senate:

*Note that they will need other states where poverty, including rural poverty is an even bigger issue, though, so they shouldn't get too libertarian.