FYI the common idiom is "case in point," rather than "case and point." The phrase represents this idea: I have a case to make (or an argument), and there is a

FYI the common idiom is "case in point," rather than "case and point." The phrase represents this idea: I have a case to make (or an argument), and there is a single element that is conclusive enough to make the whole case in and of itself. You might say, "I can address this entire case in a single point." This shortens to "case in point." The implication is that the single point you make is enough of an argument to prove your whole case.