The High Point Enterprise Fred Flagler, Staff Writer      Force of the cartoon as a medium to express what words and even pictures fail to do is strongly appreciated by Bob Snider, a printer by trade and a cartoonist by hobby.      About this time of year, Bob is in demand for appearances on Christmas programs at factory parties.  His forte is drawing caricatures while presenting a running commentary “in the light vein.”  He figures he can do about 40 cartoons along with gab in about 20 minutes.      With a modest evaluation of his own technique, Bob credits the success of his performance mainly on the ...