Theme: You think I'll tell you the theme? As if! - And if that's not enough, I'll repeat it five times.
17A. "As if!" : "AIN'T GONNA HAPPEN!"
27A. "As if!" : "NO WAY, JOSE!"
38A. "As if!" : "DREAM ON!"
46A. "As if!" : "YEAH, RIGHT!"
57A. "As if!" : "FAT CHANCE OF THAT!"
Argyle here. You get the picture? Jeff has delivered a nice tight Tuesday, with two grid spanners and a couple of long climbers, too.
Across:
1. College donor, often : ALUM. A shortened version that can encompass single and plural of both genders. Handy.
5. 401(k) cousin, briefly : IRA. (individual retirement account)
8. Garden ground cover : MULCH
13. Mount Olympus wife : HERA. The wife of Zeus.
14. Break bread : DINE
16. Novelist Zola : EMILE. The most common of the crossword Emiles
20. Halley's sci. : ASTR. (astronomy)
21. Full of vitality : GO-GO. Full of Red Bull?
22. Ideological suffix : ISM
23. Lift with effort : HEFT
25. '60s counterculturist Timothy : LEARY. "Turn on, tune in, drop out"
31. Rants about the boss, e.g. : VENTS
34. Jacob's brother : ESAU
35. Niagara Falls prov. : ONT. (Ontario)
36. Gorky Park city : MOSCOW. Song.(5:13)
37. Like hor. puzzle answers : ACR. (horizontal/across)
40. Hostility : IRE
41. Started, as a keg : TAPPED
43. P.I. : TEC. (private investigator/detective)
44. Hypnotic trance breaker : SNAP
45. "Friend __?" : OR FOE
48. Pal of Threepio : ARTOO. Star Wars droids.
50. Not at all droopy : TAUT
51. Intro makers : MC's. (master of ceremonies)
52. One might say "shay" for "say" : LUSH. Drunks don't talk so good.
54. Inevitable end : FATE
61. Honolulu hello : ALOHA. Nice alliteration.
62. Egg on : GOAD. Phrase Finder link for "Egg on.
63. Sculling gear : OARS
64. Headwear in iconic Che posters : BERET
65. Many ESPN fall highlights : TD's. (touchdown)
66. Way to be tickled : PINK
Down:
1. Cry of enlightenment : "A-HA!"
2. Film heroine with memorable buns : LEIA. My mind was boggling for a bit there but, oh, it's just another Star Wars reference.
3. Java vessels : URNS
4. "Grumpy Old Men" co-star : MATTHAU
5. Rite words : I DO
6. Modern caller ID, perhaps : RINGTONE. Different tones can be assigned to frequent incoming callers, right? I still don't have a cell phone.
7. Part of A.D. : ANNO
8. Drop-line link : ME A. Exactly like Sunday's entry.
9. Wrigley Field judges : UMPIRES. Wrigley Field is the home of the Chicago Cubs.
10. Mouthing the lyrics : LIP SYNCING
11. Red Skelton character Kadiddlehopper : CLEM. The joys of live TV.
12. Cooped-up layer : HEN
15. Bird on old quarters : EAGLE. How 'bout that; going from a chicken to an eagle.
18. Earl __ tea : GREY
19. Groundbreaking tool : HOE
24. Greenland coastal feature : FJORD
26. Company that rings a bell? : AVON. Cute clue.
27. "Marvy!" : "NEATO!" and 57D. "Marvy!" : "FAB!"
28. Green grouch : OSCAR
29. "Star Trek" velocity measure : WARP FACTOR. About 338,000 results if you Google "warp factor".
30. Word in many university names : STATE
32. Bar mitzvah reading source : TORAH
33. Didn't lose a game : SWEPT. Giants in the World Series this year.
36. Java order : MOCHA
38. Off! ingredient : DEET. Another Sunday answer.
39. Mike, to Archie : MEATHEAD. "All in the Family"
42. Upscale sports car : PORSCHE. Any Porshe owners out there?
44. Perch on : SIT ATOP
46. Like babes : YOUNG. I found this to be a little strange.
47. Dennis the Menace's dog : RUFF
49. Pay extension? : OLA. (payola)
51. Stallion or bull : MALE
53. Craig Ferguson, by birth : SCOT. The Late Late Show is hosted by Craig Ferguson since 2005. It is on after Letterman.
55. Asian tongue : THAI
56. Bring home : EARN
58. Monopoly token : HAT
59. Has too much, briefly : OD's. (overdose)
60. Clucking sound : [TSK!]