If you are a libertarian, you should never cede the moral high ground. That is one of the beauties about libertarianism, which hopefully most libertarians realize. You have the moral high ground and pragmatism on your side.
If you are ever asked about libertarianism, you don’t necessarily have to try to convince the other person of your point of view. Instead, just help them understand where you are coming from. Imagine the following conversation.
Libertarian Guy (LG): Let’s say that your neighbor is really sick and needs money for an expensive surgery to help save him. You go to another neighbor and ask if he can help out in providing any funds. Do you agree that it is ok for you to ask your neighbor for some help?
Non-Libertarian Guy (NLG): Of course it is ok to ask.
LG: Good. We agree on that point. What happens if your neighbor refuses to help out with donating money? Do you think it is ok if you take out a gun and demand that he help his other sick neighbor?
NLG: Of course I don’t think it is ok. It doesn’t matter if the other guy is sick. You can’t just take out a gun and demand money. That is violence and it would be a crime.
LG: Good. We completely agree on that point too. Now let’s say that you get together the rest of your block and you hold a vote. The majority of people on the block vote for you to take your gun and go back to that one neighbor’s house and demand some of his money to help the other sick neighbor. Is it ok to use your gun since the majority of your block thinks it is ok?
NLG: Well, I would hope that there wouldn’t be that many people who think that robbery is ok. But, of course, it doesn’t matter what they say. It doesn’t make it right. You still can’t just go up and take the guy’s money at the point of a gun just because he doesn’t want to donate money.
LG: Well, yet again, we agree. We are in agreement in all of these points. So you were wondering what makes me a libertarian. I believe if the people on your block call you or themselves a state or a government, that it is still wrong to take the guy’s money at gunpoint. That is the main difference between a libertarian and a non-libertarian. Most non-libertarians live peacefully with others and wouldn’t dream of initiating force against others. They just don’t apply this principle to the state.
End of Conversation
You can get into detailed issues about what constitutes the initiation of force and what constitutes self-defense. You can get into details about how certain property rights are acquired and where property rights should and shouldn’t apply. You can get into details about whether a state is legitimate if it only acts to protect people’s lives, liberty, and property.
But when you get down to it, the above example sums up what a libertarian is and isn’t. Get agreements from non-libertarians on the above points and then point out the one simple, yet important, difference that makes you a libertarian.