I'm a registered libertarian. I commonly see fellow libertarians using the "forced fluoridation" argument.  

No one has ever had fluoridated water poured down their throat against their will.  People can use filters or buy bottled water.

Fluoridation does not add anything but a tiny amount of fluoride ions.  Water is monitored before leaving the water treatment plant.  If dangerous levels of lead, arsenic, etc. have been found reaching the home, the problem is with the water treatment plant (or old lead pipes), not with fluoridation.   

There are no other methods of fluoride delivery that are as effective as fluoridated water.  Toothpaste, for example, provides only two hours of protection.  Likewise with tablets, which are expensive, require a prescription (because the prescriber is responsible for knowing if the local water is fluoridated or not). Fluoridated water provides round the clock remineralization via the saliva. It is easy and remarkably cheap.