The Cato Institute declares in its new policy analysis, "The Libertarian Vote," by Cato vice president David Boaz and America's Future Foundation executive director David Kirby, that the Republican Party seems to be losing the libertarian vote:
[P]olls find that some 10 to 20 percent of voting-age Americans are libertarian, tending to agree with conservatives on economic issues and with liberals on personal freedom. The Gallup Governance Survey consistently finds about 20 percent of respondents giving libertarian answers to a two-question screen.
Our own data analysis is stricter. We find 9 to 13 percent libertarians in the Gallup surveys, 14 percent in the Pew Research Center Typology Survey, and 13 percent in the American National Election Studies, generally regarded as the best source of public opinion data.
For those on the trail of the elusive swing voter, it may be most notable that the libertarian vote shifted sharply in 2004. Libertarians preferred George W. Bush over Al Gore by 72 to 20 percent, but Bush's margin dropped in 2004 to 59-38 over John Kerry. Congressional voting showed a similar swing from 2002 to 2004. Libertarians apparently became disillusioned with Republican overspending, social intolerance, civil liberties infringements, and the floundering war in Iraq. If that trend continues into 2006 and 2008, Republicans will lose elections they would otherwise win.
Not that this means the "Libertarian Democrat" is necessarily on the march either, as Nick Gillespie explained over at Cato's webzine.