Pack A Punch Meaning

(idiomatic) To be capable of having a swift and powerful effect.

Example: 1930 Victor R. Daly, "Private Walker Goes Patrolling," The Crisis, Vol. 37, No. 6 (June 1930), p199
  Memphis Bill was known to pack a punch.
2009 Mary Fitzpatrick, Lonely Planet East Africa, Lonely Planet, p77
  If gorillas do fight, injuries can be very serious as these animals have long canine teeth and silverbacks pack a punch estimated at eight times stronger than a heavyweight boxer.
1942 Robert Allen Griffin, School of the citizen soldier: adapted from the educational program of the Second Army, Lieutenant General Ben Lear, commanding, D. Appleton-Century Company, Incorporated, p500
  They go in for statements, slogans, cartoons, pictures, and posters that "pack a punch."
2003 Ronald A. Berk, Professors are from Mars, students are from Snickers: how to write and deliver humor in the classroom and in professional presentations, Stylus Publishing, LLC., p30
  Second, prepare the choices as one-liners. Each one should pack a punch and be so polished that it will jump off the screen into the minds of the audience and create a funny picture.