A strong Libertarian candidate can attract votes from BOTH mainstream parties, not just Republicans. Aren't voters registered specifically as republicans or democrats in the minority among all voters?
Doubtful. The democrat vote is mainly based on race, getting freebies, preferences of one form or another and clueless women who think rush limbaugh is going to take away their birth control pills. Not a lot of deep thinking there.
Libertarians, ie the real ones, not fakes like that democrat-plant idiot, tend to overthink politics. It's great to have principles, but do you really want Obama appointing a couple more Supreme Court justices and ten or fifteen appeals court judges? I don't. If the republicans would wake up from their coma, they would come out for legalized pot and suddenly they look a lot better to libertarians.
Bottom line, if you want to pay for some slackers health care insurance, have the courts taken over by Bill Ayers radicals and have 30 million more illegal mexicans here, by all means vote libertarian.