> problem is not turnout. What the Democrats

You’re only looking at the general. 5% more eligible voters turning out to primaries could easily flip the outcome, or at the very least, signal a political bloc that will show up for someone. 5% of eligible voters contacting their electeds would represent a 25% increase from baseline; this is the sort of power that makes e.g. regulating supplements impossible. (If you try your office’s phone lines get blown up by constituents.)

> unable or unwilling to change their platform

Changing your platform for a group that doesn’t turn out is incredibly risky. Sometimes it works. Most of the time, they keep up not turning out.