Symbolism, Imagery, Allegory
In The Assistant, the wind is a symbol of fate and its power over free will:
[Frank's] life had pushed him wherever he went; he had led it nowhere. He was blown around in any breath that blew, owned nothing, not even experience to show for the years he had lived (7.2.6).
Fate is an overpowering force that often moves without rhyme or reason, just like the wind. It moves Frank in one direction and then another. He is like a willow tree in the gusts, but without the elegance or grace.
Morris has the same perception:
The March wind hastened him along, prodding the shoulders. He felt weightless, unmanned, the victim in motion of whatever blew at his back; wind, worries, debts, Karp, holdupniks, ruin. He did not go, he was pushed. He had the will of a victim, no will to speak of. (8.5.11)
Both of these men feel that life has moved them to where they are, as if they had little or no say in the matter. They are victims of circumstance, unable to climb out of the hole they're in. Bad luck just keeps pushing them back down.