On a political spectrum, the term libertarian should relate to anti-authoritarian

Sure, but we're not on a political spectrum. Political names are codified as part of a propaganda campaign advanced by the original party leaders. Democrats, Republicans, Greens, Libertarians, Constitution Party, Reformers, Socialists (both National and International) are - at their heart - marketing taglines, fully divorced from the beliefs and policies of their constituencies.

Ron Johnson said in a single breath that he was a libertarian and opposed the legalization of marijuana.

He's only the latest iteration. I might send you back to Murray Rothbard and Ludwig Von Mises, the OG American Anarcho-Capitalists, both of which had some bizarre theories about what constituted "small government" from the perspective of a Washington DC insider.

Marijuana consumption, much like miscegenation and immigration and unionization, might seem at first glance to be a consequence of independent human agency. But they all carry potential social consequences, particularly against individuals with claim on private property.

By getting high, you're turning yourself into a public nuisance - possibly even a violent threat - to your landlords. By crossing international borders, you are acting as a member of an invading army and threatening the economic livelihood of prior landed gentry. By unionizing, you are forming a labor cartel - almost certainly crafted through the violent agitation of wicked foreign governments employing the mind-altering ideology of Marxist-Leninism. By miscegenating, you are robbing me of the commodity of a virginal daughter to be traded on the open market.

All of these are acts of violence that threaten the property and security of the rightful landed man. We must rely on the good, honest, well-trained battalion of law enforcement officers in order to uphold the security of that property.

US politics is unfortunately entrenched in tribalism rather than searching for the right tool to match a job or solve a problem and maximize outcomes

The US is focused first and foremost on the claim to private property and the fruitful extraction of wealth from that property. Libertarianism, as an ideology, revolves around defining the extent to which individuals can go in defending that property from evil foreign aggressors and corrupted domestic residents. It endorses a state solely for the upholding of this ideology.