Libertarianism is filled with wolves in sheep's clothing. People with anti-liberty ideals, when they share some pro-liberty ideals with libertarians, believe we share all their ideals. We don't. In fact, their anti-liberty "values" are disgusting.
I know there are also those who claim to be "conservative" or "liberal" who can't meet the minimum measure to fit the bill. Regardless of where you stand, I'm sure you can relate to the problem of wolves in sheep's clothing among any group.
Someone can be "libertarian leaning" while still not being libertarian. They are not the ones to learn from if you truly want to understand liberty.
Over the years I have seen people claim anyone who points out one of these frauds is falling into the "No true Scotsman" fallacy. If you aren't familiar with this fallacy, it's like claiming "No libertarian would do that!" If shown someone who claims to be a libertarian doing exactly that, they cry "No TRUE libertarian would."
However, the fallacy doesn't apply where there is a clear definition of what membership in a group entails, and it is being violated. For example: "no honest man would lie" isn't a "No true Scotsman" fallacy, because liars are not honest.
Sometimes he really isn't a Scotsman.
A libertarian is one who advocates maximum liberty and minimum government. My observation is that "minimum" anything is zero; you may believe in some other minimum.
"Maximum liberty and minimum government" is reached by rejecting aggression. Libertarians accept the fact that no one has a right to use force against those who are not being violent nor violating private property, and no one has a right to violate the property of others. A job can't grant you a pass, either.
Anyone who follows this is a libertarian whether he knows it or not, and those who don't accept it aren't libertarian no matter what they may say. By definition. A horse is a horse, and nothing else is.
The worst anti-libertarian impostors are always politicians. Ofttimes they don't claim to be libertarian, but are mislabeled as such by the media which doesn't understand the politician nor libertarianism. This gets old.
It is also divisive. Libertarians who believe in trying to vote their way to more liberty are constantly fooled into supporting politicians who don't reject aggression and theft, just because they believe another politician would be worse.
If you vote and value liberty, look at what the candidate does, not what he is called.