If that's moving up, then I'm moving out

Blue Virginia gets more blue after seeing a story that 40 percent of Arlington County residents plan to leave in the next five years.
At least they learn basic supply and demand.
Places like Arlington have enacted the types of policies (and/or failed to enact the types of policies) that, both explicitly and implicitly, have constrained the supply curve for housing (e.g., kept that supply curve from shifting out sufficiently) while the demand curve (the overall number of people who "demand" housing in Arlington) has shifted out sharply, along with the region's population.
Lots of liberal ideas depend on increasing housing density, and more people wanting to live in compact, walkable neighborhoods.
Except they can't bridge their desires and the reality of how people want to live.