In On the Impossibility of Limited Government…, Hoppe says:
…It is necessary to recognize that the ultimate power of every government – whether of kings or caretakers – rests solely on opinion and not on physical force. The agents of government are never more than a small proportion of the total population under their control. This implies that no government can possibly enforce its will upon the entire population unless it finds widespread support and voluntary cooperation within the nongovernmental public. It implies likewise that every government can be brought down by a mere change in public opinion, i.e., by the withdrawal of the public’s consent and cooperation. (italics added)
So you see, voting is an act of support. It is how we consent to and cooperate with our government. When we vote for someone, we are agreeing to give him certain powers over our lives. If that politician does not share our values, then we become complicit in our own undoing. We become agents of the very state whose policies are antithetical to the cause of liberty. In other words, when we vote for someone who is not an ideological peer, we are supporting and furthering the cause of our own enslavement.