NY Times Crossword
June 15, 2016
Jason Flinn (#1-4)

The answers to the clues below will have something in common that can be described by a common expression meaning "rant continuation."

1. Special perception
2. Power source for a subway train
3. Unwanted tag-along 
4. Country that's an extremely close American ally, so to speak
5. Beginning of overtime in baseball
6. Length, width, depth, and time

Answers:

1.  Sixth sense
2. Third rail
3. Fifth wheel
4. Fifty-first state
5. Tenth inning 
6. Fourth dimension

Common Expression:

AND ANOTHER THING

Explanation by JA: Each answer is one more than the usual number of its subject:

Five senses
Two rails
Four wheels
Fifty states
Nine innings 
Three dimensions