I left the Libertarian Party in 2004 when presidential candidate Michael Badnarik asked supporters to wear black on the anniversary of 9/11 "to mourn the deaths of the thousands of people who have died as a result of U.S. government policies".
Libertarians are often idealistic and myopic, ignoring the real world in pursuit of their goals, unable to compromise their principles. A little pragmatism is called for in the real world.
Yes, although I was a card-carrying member of the Libertarian Party in the 1990s, their pathetic response to the 9/11 attacks caused me to lose confidence in the party. And "pathetic" is putting it kindly.