Nate Silver's Five Thirty Eight blog had a post a couple of days ago entitled "Poll finds a shift towards more libertarian views." His measure of libertarianism involved two questions, one about whether "the government is trying to do too many things that should be left to individuals and businesses," the other about whether "the government should promote traditional values" or "not favor any particular set of values." Both of them are meaningful questions, but I don't think that either gets at the heart of the libertarian position, which I would summarize as saying that nothing should ever override individual rights. Some things that have a direct relatioon to core libertarian principles are opposition to mandatory seat belt laws and mandatory helmet laws for motorcyclists. Neither is a big issue in mainstream politics, but there have been a few questions.
Would you favor or oppose a law that would fine a person $25 if he did not wear a seat belt while riding in an automobile? (Gallup)
1973: 25% 71%
1977: 17% 76%
1977: 17% 78%
1982: 19% 77%
1985: 35% 59%
1988: 54% 43%
Many states have primary seat belt laws that allow police officers at stop a driver solely for not wearing a seat belt. In other states, with secondary laws police must have some other reason to stop a vehicle before citing an occupant for failure to buckle up. Which type of seat belt law do you support--primary or secondary? (Public Attitude Monitor 1996)
Primary 44% Secondary 45% Neither (vol) 8%
Of course, not all of the opposition in 1973 reflected libertarian principles. Most of it was probably just "we've never done that before, why start now"? And the 1996 question is quite different. But the 8% is of interest as an indicator of the number of committed libertarians.
Some states have laws that require motorcyclists to wear helmets. Studies show that the use of helmets greatly reduces deaths and serious injuries among motorcyclists. On the other hand, some people are opposed to helmet laws because they claim such laws limit a person's right to choose what they do. What is your opinion? Do you strongly support, moderately support, moderately oppose, or strongly oppose motorcycle helmet laws? (Public Attitude Monitor)
1990: strongly favor 76% favor 14% 5% moderately oppose 3% strongly oppose
1996: strongly favor 64% favor 20% 7% moderately oppose 6% strongly oppose
Some people believe that motorcycle helmets should be required because they reduce deaths and serious injuries. Others oppose helmet laws because they limit a person's right to choose what they do. Because of these different viewpoints, state laws on motorcycle helmets differ.... Do you think all motorcyclists should be required to wear a helmet when riding a motorcycle? (Public Attitude Monitor)
2001: Yes 79% No 20%
The 1996 figures add up to 110, not 100 (if people who don't know are counted), so the reported totals must have mistakenly added 10 to one of the first two categories. Either way, there was some weakening of support for mandatory helmet laws between 1990 and 1996. The 2001 question is somewhat different, and I think the way it's worded may be more favorable to the "no" position than the earlier questions. But for what it's worth, it points towards growing opposition.
The conclusion: at least we can rule out "no change."