What the speaker meant by tomorrow is "in the future when there is equality".
The poem is about racism in America again the black and how the black responded to it.
The blacks in America are hoping for equality in the future when they will be treated the same way whites are being treated and they will enjoy the same privilege as the whites.
You would use a comma. The semi colon acts when both what is in front and behind it can stand alone as a sentence. “With technology in the hands of so many people” does not make sense standing alone.