Across:
   7. Thanks fast player with natural ability (6)
   8. Crook, then a GOP figure? (8)
  10. Rotten fruit & ale, as you don't want your serve to be in 12's caper? (8)
  11. Score is unusual when adopting ultimately static game of 14 16 (6)
  12. One that served starts to join in melee with one that delivers (3 7)
  14,17. One that struck starts to aim low at night with one that fleeces (4 7)
  15. Much respected second being ousted, went back (7)
  17. see 14
  20. Behind, president's time is running out (4)
  21. see 21 down
  23. see 4 down
  24. Concern for 16 as bully thrashed student leader (8)
  26. One that embraced art left to the west, after convincing first one that embraced art of 4 23 (8)
  27. Poles invaded by crazy dude without much notice (6)
Down:
   1. African country invaded by a western country (6)
   2. see 25
   3. View from height (where height ultimately replaces length) (8)
   4,23ac. One that played starts to chance his arm, risking position with one that manages the game (7 6)
   5. Hotel in Casablanca mostly wrecked in drunken revelry (10)
   6. Fellow with party policies (8)
   9. One that was obsessed with appearance shifted ropes (5)
  13. Bush followed Clinton's lead a lot, as he didn't want to spend much (10)
  16. 21 21 perhaps courted a revolution (8)
  18. He's Leeds-crazy, whatever happens (8)
  19. Herb growing in garden and surrounds I notice (7)
  21,21ac. One that taught sir to aim arms one that runs amok (5 10)
  22. Woke hipster who guru says made grand finals (6)
  25,2. One that plays bass guitar with unknown one that rings (4 4)