ACROSS
 1 Such people as Johnson? They might handle some of your security problems by design. (13)
 9 Draws the line when it comes to regulations! (5)
10 Spreads it on thick, obviously. (7,2)
11 City of New York, especially if South instead of West. (7)
12 Part of the Capitol tour, and not well managed. (7)
13 Colors associated with St. Louis, possibly. (5)
14 He cashed a check for possible capital problems. (9)
16 A long time ago, or possibly just over 50 years? (6,3)
18 A clever saying, conjecturally, by design? (5)
19 Run of the mine or clay pit, possibly. (7)
21 English poet, good enough when young but a wonder at fifty! (7)
22 One way to change nacre into tin? (9)
23 Certainly not the 14 down part. (5)
24 20 are undue trouble when retired. (13)
DOWN
 1 See 8 down
 2 Not necessarily speaking with a forked tongue. (9)
 3 Cattlemen didn’t like such birds. (7)
 4 Even the smartest set possibly includes the underground types of London. (5)
 5 Change is eternal at such change. (9)
 6 Was she improved by her midnight habits? (7)
 7 In short, is she to seek judgment? (5)
 8 and 1 down Evidently a whisper is appropriate with the president’s club. (5,6,3,5,1,3,5)
14 The queen of the maritime service? Bill might mention her first! (9)
15 The language of a feverish child, when about 10? (9)
17 Most of the class is in the pen, conceivably, so hold close! (7)
18 Obviously a piece by a French composer. (7)
20 Shows signs of being almost worn out clothes! (5)
21 Less than bright part of the room, or only appearing so. (5)