There shouldn't be a libertarian party. Everybody should be his own candidate.
Exactly. The very concept of a "libertarian party" is an oxymoron.
Political parties are about coalition-building, structure, organization, compromise, and incremental, collaborative progress.
The vast majority of modern libertarians--at least the American strain--are all about independence, personal control, certitude, and a fundamental aversion to the organization and structuring of power. A party of this nature looks like...well, it looks exactly like what we saw this week--from the overhead-projected Excel spreadsheet tally of votes right on down to the candidate with the large Iron Cross tattoo who decided to perform a burlesque show on a dare.
Libertarians will never be more than a fringe force on American politics, simply because they're intrinsically unwilling to build kind of structured organization that makes it possible to win tens of millions of votes.