A tester of a puzzle? (Solution No. 3,269)

The names of thirteen current US senators are strewn throughout the chamber.  The names of the Republican senators are more crossword-friendly than the Democrats, which might be to the chagrin of The Nation readers.  Eight of the thirteen are Republicans (colored red in the solution), three are Democrats (blue), and the two nominal independents who function as virtual Democrats.

The short names result in the grid having no long lights, so there were more clues than usual (see Hozom's September 21 comment: Counting Words).  The grid is spiced up (and an additional connection added) by the pair of three-letter words in the center.  

By my count, there are six more senators that could reasonably go into a crossword: Boxer, Carper, Coons, Graham, Kirk, and Tester.  There are more if you stretch a little and allow other proper nouns as definitions.  

Difficulty (by standards of this weekly puzzle):  Mostly easy, especially if you follow politics.

Political content: see theme.  

Musical content: 6d (part of wordplay).

Solution and explanation below the fold.

Legend: "*" anagram; "~" sounds like; "<" letters reversed; "( )" letters inserted; "_" or lower case: letters deleted; "†" explicit in the clue, “^” first letter or letters, “{“ relocated letter or letters

Across

1a	*SESSIONS	*[NOISE + SS]  “repeatedly in one case” is a tip that one of the letters in NOISE is used multiple times in the anagram
6a	*COATS	*TACOS (anagram indicated by “shredded”)
10a	*ON GUARD	*A GROUND (anagram indicated by “breaking”) A very slight bending of the rules, but you’ve been amply warned.
11a	DE(<ADP<)AN	DEAN (“school official”) containing (“takes”) <PDA< (“handheld device”, reversal indicated by “back”)
12a	_KING_	rumplestilts_KIN G_leefully (hidden word indicated by “traps”)
13a	PA(U)L	PAL (“friend”) containing (“embracing”) ^U^nitarian (first letter indicated by “leader”) The evangelist referenced is St. Paul (Saul of Tarsus).
14a	F | LAKE	^F^rigid (first letter indicated by “source”) + LAKE (“body of water”)
15a	{R{EMOTE	EMOTE{R{ (“expressive person”, relocated letter indicated by “back at the front”)
17a	RUB NOSES	Spoonerism of NUB (“point”) + ROSES (“flowers”) A play on the pop cultural image of Eskimo people rubbing noses as a greeting
19a	DIP_	^DIP^hthong (“two vowels”, selection of first three of nine letters indicated by “one third”) Clues like this make it worth having some three-letter words in the grid from time to time.  Not to mention the unusual pattern in the center.
20a	PICK(E_T)ED	PICKED (“chose”) containing (“to surround”) E_stablishmen_T (first and last letters indicated by “entrance and exit”) Exclamation point since “chose to surround” is also the definition
21a	SH(AD)OW	AD (“commercial) contained in (“interrupting”) SHOW (“program”)
24a	BLUNT	Double definition (“blunt” is a slang term for a cigar filled with marijuana)
26a	<REED<	<DEER< (“ruminant,” reversal indicated by “returns”)
27a	B(U)RR	BRR (“it’s cold”) containing (“around”) j^U^ne (second letter indicated by “second of”)
29a	*IFFIEST	*FIFTIES (anagram indicated by “counterfeit”)
30a	*SHU(T)TLE	*HUSTLE (anagram indicated by “criminal”) containing (“smuggling”) loo^T^ (last letter indicated by “ultimately”)
31a	HATCH	Double definition
32a	*SENATORS	*TREASON (anagram indicated by “unacceptable”)

Down

2d	ERGO | NO MIC	ERGO (“therefore”) + NO MIC (“with no amplification”)
3d	SCAR_	^SCAR^cely (selection of half the word indicated by “half)
4d	OR | DEAL	OR (†) + DEAL (“agreement”)
5d	*SADDLE UP	*SLAP DUDE (anagram indicated by “senseless”)
6d	CHA(FF)IN | CH	FF (“very loud”) contained in (“held by”) CHAIN (“string”) + CH (“church”)
7d	_ALPHA_	cruci_AL PHA_se (hidden word indicated by “part of”)
8d	SAN(<DER<)S	<RED< (“flushed”, reversal indicated by “up”) contained in (“in”) SANS (“without”)
9d	COR(K)ER	CORER (“kitchen utensil”) containing (“to keep”) K (“kosher”)
16d	*T(WENT)IETH	*IT THE (anagram indicated by “blast”) containing (“outside”) WENT (“disappeared”)
17d	RID_	RID_e (“trip”, omission of last letter indicated by “cut short”)
18d	*SODBUSTER	*DEBTS OURS (anagram indicated by “reorganized”)
19d	*DETRITUS	*I TRUSTED (anagram indicated by “unfortunately”)
20d	PU(B | LI)SH	PUSH (“sell drugs”) containing (“covering”) B (“Brooklyn”) + LI (“Long Island”)
22d	~WARREN	~WARRING (“going at it”, homonym indicated by “we hear”)
23d	*NELS | ON	ON (†) following (“after”) *LENS (anagram indicated by “cracked”)
25d	UN(F)IT	UNIT (“one”) containing (“grabbing”) ^F^ood (first letter indicated by “a piece of”)
28d	JUST	Double definition