Why is it so freaking hard to get Democratic voters to vote

[Metaphorical]

19. Institutional Bias, Suppression, Gerrymandering, and Disinformation

all play parts, but I think that not understanding the constituencies of the parties may also be a part of the issue.

The GOP has in general been a small party with a very narrow agenda since at least the 1960s. It represents a very limited set of constituencies:

1. The old guard (petroleum economy) wealthy individuals and those people working in those fields.
2. Christian fundamentalists and social conservatives, not all of whom are white are white or male.
3. Rural (and mostly inland) constituencies which often work in agriculture, resource extraction (farming, mining, oil resources), the automotive industry and elsewhere.
4. The military, especially at the enlisted level.
5. Law Enforcement and security.
6. Those who generally have access only to a high school education.
7. People who are predominantly in older school sales, marketing and management.
8. Conspiracy theorists who are convinced the government is about to launch an imminent invasion of their houses.
9. GOP Team Players
10.Libertarians (loosely).

The Democrats are the larger party, but the party is also a looser coalition made up primarily of those who are not Republicans:

1. The young Turks (the electrical/electronic economy) wealthy individuals and those people working in those fields.
2. Religious liberals, agnostics and atheists.
3. Coastal urban and suburban constituencies, especially in high tech centers.
4. College-educated voters, especially in STEM, education, and artistic careers.
5. Government employees, outside of security and the military.
6. Social activists.
7. Creatives.
8. Most urban minorities.
9. Environmentalists.
10. Democratic Team Players.

The problem of course is that this is a group that is both diverse and not all that well united on all things. Moreover, many formerly Democratic stalwarts (such as unions) have become more and more entrenched in the GOP, especially in the South, Miidwest and Landlocked West.

It is clear from the above breakdown that the Democratic party today only marginally overlaps with the Democratic party of fifty years ago, and that the progressive agenda (speaking as a progressive) is largely the agenda of the coastal urban middle and upper class. This is where the country is going, culturally, but I do think a lot of Democrat activists tend to have blinkers on about what the party actually represents, and for many in the country that feel they are regressing its far easier to envision the Democrats having nefarious agendas when in general they are just trying to bring the US up to the same standards as much of the rest of the world.

There's another aspect here that I think is important. Democrats in general tend not to be that ostentatious. We value competence over confidence, which is part of the reason that having TFG in office grated so heavily on most progressives' nerves. The problem unfortunately, is that should the Democrats succeed with their agenda, it will be because the population will have tilted far enough into the urban direction that the petroleum economy will have withered away.