The role of the politician is ideally to serve the wishes of the public, not to impose their own agenda upon them. Sadly, many people attracted to public life seek to make the world over in their own image. It is these “values based” politicians we need to be wary of.
There is nothing wrong with people having values- this is inevitable- but it is important that such people are not chosen to lead when their desire is to usurp the free will of others, forcing them to live according to the values of the leaders.
Such political candidates seek to outlaw behaviors they find objectionable, often on supposedly "moral" grounds. In this way they seek to overthrow the free will of the individual. This results in a kind of imprisoning of the public- by limiting their choice of behaviors- by their elected officials so that the officials and their supporters can feel comfortable.
Those who value freedom need to be on guard to ensure they don't vote for such individuals, discouraging their attempts at muzzling human behavior.