The answers to the clues below will have something in common:

1. Battling - intellectually
2. Bang for your buck
3. $7.50 an hour, in some states
4. Piano piece that's longer than its name suggests
5. Pioneering American blues singer
6. West Point subject
7. Classic dictionary
8. Movie about Helen Keller and her teacher
9. Boxing category
10. Agatha Christie, for one
11. Operetta by Franz Lehar
12. Poor husband choice

Answers:

1. Matching wits
2. Money's worth
3. Minimum wage
4. Minute Waltz
5. Muddy Waters
6. Modern warfare
7. Merriam-Webster
8. (The) Miracle Worker
9. Middle-weight
10. Mystery writer
11. (The) Merry Widow
12. Mister Wrong

Credit: NY Times Crossword - June 30, 2013
Alex Vratsanos and Jeff Shen
MATCHING WITS  (#1-6)