In every dark hour of our national life a leadership of frankness and vigor has met with that understanding and support of the people themselves which is essential to victory.
which concept does this sentence best convey?

well basically since ima beginner people will answer any subject "right away"and if you get more points you could ask more questions or if you answer someone's question you get points

people wont do this for 10 points you need at least 50

(you didn't attach a copy of the poem, but i'm answering as best as i can)

since a simile compares two unlike things using like or as, it kind of gives an item the ability to do something it can't.

example: "the player was like a tiger on the field"

in this sentence, the simile conveys the idea that the player was fast and strong, like a tiger.