Why does the us supreme court generally defer to precedent descions?

Ineed to try to get this right so i can get a good grade so can someone me

The 15th amendment to the u.s. constitution, ratified in 1870, deals with what issue? a. prohibition of alcohol b. voting c. declaring war d. free speech

Which side was right? write a paragraph in which you explain which side made a stronger argument and why. remember to use evidence from the lesson and from primary source documents you have read.