Theme: W-I-D-E - in the circles. If no circles, the reveal should make it clear anyway.
17A. Caribbean island group: WEST INDIES
23A. Independence Day colors: RED, WHITE, AND BLUE
37A. Auto visibility aid with intermittent settings: WINDSHIELD WIPER
48A. "How about that!": "WELL I'LL BE DARNED!"
60A. Extensive ... and what's literally seen in this puzzle's circles: WIDESPREAD. (wide spread)
Argyle here. A few of us may suffer from WIDESPREAD but let's not go there. This couple gave us a Tuesday puzzle on March 14.
Across:
1. Fancy tie: ASCOT
6. Facts and figures: DATA
10. Herring family fish: SHAD
14. Pageant topper: TIARA
15. Broadcast with greater image resolution, as TV shows: IN HD. (High-Definition)
16. Sign over: CEDE
19. Golf outing spoiler: RAIN
20. Mature: AGE
21. "Give all thou __": Wordsworth: CANST. Inside of King's College Chapel, Cambridge.
22. Helping hands: AIDES
26. Olive product: OIL
27. Vicinity: AREA
28. Piano-bass-drums jazz group, e.g.: TRIO
31. __ apso: dog: LHASA
34. Bumped into: MET
41. Atypical: ODD
42. Ballplayer with "SD" on his cap: PADRE. San Diego Padres.
43. Quartet that covered "Woodstock," initially: CSNY. (Crosby, Stills, Nash & Young)
44. Jamaican fruit: UGLI
46. Royal flush card: ACE
56. Cereal grass disease: ERGOT
57. Broadcaster: AIRER
58. "Don't Bring Me Down" rock gp.: ELO. (Electric Light Orchestra)
59. From the top: ANEW
62. "The __ of the Ancient Mariner": RIME
63. Actor Guinness: ALEC
64. Augment: ADD TO
65. Gardener's purchase: SEED
66. Playbill listing: CAST
67. Cuts with a light beam: LASES
Down:
1. Battling it out: AT WAR
2. Prolonged battle: SIEGE
3. Scoped out with bad intentions: CASED
4. Table scrap: ORT
5. Meditative Chinese exercise: TAI CHI
6. Neglected to: DIDN'T
7. Ouzo flavoring: ANISE
8. Consonant before iota: THETA. ϴ, eighth letter.
9. Promos that interrupt programs: ADS
10. Old manuscript copier: SCRIBE
11. Illumination on helmets: HEADLAMPS
12. Farewell: ADIEU
13. Tightly packed: DENSE
18. Polished body part: NAIL
22. Play to __: tie: A DRAW
24. Lumberyard purchase: WOOD
25. Former OTC watchdog: NASD. [Over-the-counter (stock) / National Association of Securities Dealers (merged with Financial Industry Regulatory Authority in 2007)]
28. Couple: TWO
29. Get __ of: discard: RID
30. "I'd like this favor": "INDULGE ME"
31. Cookie jar cover: LID
32. Ship's pronoun: HER
33. Malt brew: ALE
35. Poetic twilight: EEN
36. "These are the times that __ men's souls": Paine: TRY
38. Bowler's challenge: SPLIT
39. Flag down, as a cab: HAIL
40. Cake decorator: ICER
45. Emitted an aura: GLOWED
46. Orange drinks: ADEs
47. __ tunnel syndrome: CARPAL
48. Has on: WEARS
49. Orange Muppet: ERNIE
50. Muhammad's boxing daughter: LAILA
51. __ one's time: waits patiently: BIDES
52. Standing straight: ERECT
53. Non-negotiable things: NEEDS
54. Fill with glee: ELATE
55. Extinct birds: DODOs
60. WWII GI Jane: WAC. (Women's Army Corps)
61. Dietary guideline letters: RDA. (Recommended Dietary Allowance)
Argyle