F tier - cops, military officers, coast guard, Immigration and custom inspectors
F+ tier - DAs, military, TSA officers
D tier - doctors
D+ tier - psychologists
C tier - nurses
B tier - teachers, private defense attorneys, tax collectors
A tier - social workers, janitors, government agency workers (DMV workers, office jobs, etc), public defenders, pro-bono defense attorneys
S tier - postal workers, firefighters, sanitation workers, veterinarians, anesthesiologists, park employees, forest rangers
Rest in Power p.a.t.c.o, martyrs in the fight for labor rights
EDIT: I'd like to add that this is mostly US-centric. In other countries, doctors probably range from B tier to S tier. As for defense attorneys, I honestly don't know enough about their demographics to determine how many of them are Alan Dershowitz and how many are actual public servants.
Which workers are expected to support action to reduce their income? And yet, majority of physicians DO support single payer now even though it would likely reduce their income (source). American College of Physicians even officially endorsed single payer (source). AMA is somewhere in between but still supports major overhaul. I’m a doctor and fully support M4A, and I suspect most young doctors do as well.
Workers that deliver significant benefits to society? I wish there was more employment for new grads in my field even though this would depress wages in the long run.
I would also note that single payer doesn't remotely mean the sorts of reforms that would actually ensure everyone has access, and I'm not sure the price gouging that goes with Medicare wouldn't similarly occur if its dreadful model was expanded.