1 Snack served by fiesta compañero (4)

 3 Aim ____ at close range (5-5)

 9 Handles anxieties without a hint of finesse (4)

10 Overall responsibility: you pay a tax when you cross it? (4,2,4)

12 Herb originally overtook retreating wild ass (7)

13 Tried, vs. challenging and treacherous core of adversity!! (7)

14 Bring up acclaim with a late start (5)

16 Baggage of wench antedates magic (9)

19 After opening, men start to tint panel for a coat of arms (9)

20 Immersed in bile: umbilicus and part of the intestine (5)

21 Bottles a small amount of retsina in coffee shops (7)

23 Insignificant rent-collecting in end of month (7)

25 Republicans invading a vehicle passage with a commercial aircraft (5,5)

26 Ivins discussed in The Nation (4)

27 Prosecute a criminal in the universe beyond earth’s atmosphere (5,5)

28 Song that man vocalized (4)

 1 and 18 After Independence Day without much light, raise racket about beginning of night time—this might be next after a sequence of words taken from Across solutions (3,6,9)

 2 Wish misfortune upon dogs, the source of evil (5)

 4 Cool genie disturbed geological period (9)

 5 Seen in the mirror, incorporating Democrat’s requirements (5)

 6 Splits, if splitting to polish up positively charged particles (12)

 7 Liquor with a drop of absinthe, as six eat up (4,5)

 8 lang, having taken in view, entered (5)

11 Adopt the story and speak (4,3,5)

15 Make sense of housepainter prettifying interior (9)

17 Before a stimulant, pet is in a stupor (9)

18 See 1

21 Tropical tree around California: orange (5)

22 Doctor helps lug (5)

24 Gland making Emma lose big, at first (5)
 

ACROSS 1 & 11 2 defs. 6 anag. 10 SWA([t]HI[s])L + I (laws rev.) 12 B(Y + P)ASSES 13 anag. 15 & 20 anag. 16 LIMO + N 18 HOSE + A 23 WE + EVIL 25 anag. 27 LEO(TAR)D (Dole anag.) 28 D + ETOURS (routes anag., &lit.) 29 “sticks” 30 HELL + OK + [w]ITTY
 
DOWN 1 ROSE + BAY 2 2 defs. 3 REIS + SUE 4 M(AIDE)N + AUNT (tuna anag.) 5 even letters 7 HO[t] + UND 8 anag. 9 S + CRAWL 14 anag. 17 2 defs. 18 HG + WELLS 19 hidden 21 NUN + AT + AK 22 STOPS + B[erkele]Y (spots rev.) 24 E + BONY 26 [h]EDGE