Across:
   9. Strangely rich in ore and wild animals in Africa (9)
  10,26. Somehow gains power as 2 27 resigning in '73 (5 5)
  11. Belief in greed ultimately penetrating rotten core (5)
  12. Got rid of old bias he developed (9)
  13. Game dad played, until hurt (7)
  15. Symbols of power as serving Democrat is embracing Anglican (7)
  17. Nothing on 27? He said he's not a crook! (5)
  18. Tricky Dicky yields, die cast (3)
  19,5dn,22dn. Long time position of 4 8 with rogue shire 'neutral', i.e. moody (5 8 6)
  20. Chart a musical comeback entertaining island (7)
  22. Program photographing from above and inside last disaster (7)
  23. Taking a couple of minutes, redirected 20 mail to island (9)
  24. It could be red-hot anger at rookie's promotion? (5)
  26. see 10
  27. Playing is pretend job (9)
Down:
   1. They make things more acceptable, and creep tends to develop (10)
   2. Gambling, prostitution, etc. as part of civic engagement (4)
   3. Something going down fast to swamp most of gang (8)
   4,8. Long time sleeper, a real wildcard (if so far unelected) ends as 27 from '74 (6 4)
   5. see 19 across
   6. Union with time running out as motion of deputies observed (6)
   7. Venues sling Butch out (10)
   8. see 4
  14. Making the most of what's said, I inform (10)
  16. Cooking waste meets confectionery (10)
  18. Mollusc? All op shops have molluscs! (8)
  19. Safety installation in hospital turning up someone being dishonest with genetic material (8)
  21. Ejected fourth row; next's fifth to tenth (6)
  22. see 19 across
  23. Sadly, no knockout for tree-huggers from 23 across (4)
  25. Coward's song (4)