Galileo and the Inquisition
The claim that academic tenure is just one more perk for ineffectual slackers who (in the minds of many) luxuriate in only working ten months of the year is ... ill-informed. The rhetorical conclusion that elimination of tenure will eliminate the dross from the teaching profession and will lead to radical improvements in test grades and skills acquisition is, put as kindly as possible, egregiously naive. Bottom line: attacks against academic tenure are no different than those against collective bargaining.
The achievement of tenure as a legitimate construct of academic freedom harkens back to the McCarthy Period sixty years ago, when teachers could be fired if they allowed topics to be introduced and discussed in the classroom that might offend school boards, religious groups, or dominant government policies.