The question of parents having the right to choose if their child gets vaccinated has turned into a more contentious issue over the past decade, especially recently, with a series of measles outbreaks happening across the country.
“In U.S. constitutional terms, there are two competing arguments,” says Associate Professor of Political Science Elizabeth Bussiere.
Proponents of mandatory vaccination are on one side, while those who argue optional vaccination based on personal liberty are on the other.
Pro-vaccinators believe the Tenth Amendment states “police powers” are obligated to enforce mandatory vaccination.
Police power is the state capacity to maintain the health, safety, and welfare of residents. This capacity is exerted by the executive and legislative subdivisions through laws and regulations.
“There is power to force parents to have their children vaccinated as a matter of protecting public health (not just the health of their own kids).”
Contagious diseases like measles can proliferate across the unvaccinated and newborn infants too young for immunization. 
State enforcement critics argue individual freedom should allow the choice to opt out of vaccination. This is rooted in the value of liberty protected by the Fourteenth Amendment’s Due Process Clause, whereby parents can make decisions on behalf of their children. This value of liberty could also cover the privacy to make the decision.
“To the extent that people object to vaccinations [on a moral basis], the First Amendment right to freedom of speech (which includes freedom of belief) comes into play,” says Professor Bussiere.
Should the vaccination issue continue to be important to people, it may recieve attention in the 2016 race. Bussiere believes there is a partisan dimension to the debate. 
Democrats will likely think it’s the role of government to protect the public, which the decision to not vaccinate affects. Republicans are more likely to consider mandatory vaccination too intrusive. 
Hillary Clinton endorsed vaccination on Feb. 2 with the Tweet, “The science is clear: The earth is round, the sky is blue, and #vaccineswork. Let’s protect all our kids. #GrandmothersKnowBest.”
Governor of New Jersey Chris Christie has tried to “thread the needle,” according to Bussiere. Christie supports vaccination, but believes parents have the final say. Former Florida governor Jeb Bush and Libertarian candidate Rand Paul have taken similar positions.
Bussiere thinks Republicans have to be careful. As she states it, “[Republican candidates] have to shift to the right to ‘mobilize’ their ‘base,’ and the vigorous anti-government wing, such as the Tea Party, and the religious right are important constituencies.”