Libertarian voters make up 4% of the nation’s likely voters and they favor Barack Obama over John McCain by a 53% to 38% margin. Three percent (3%) would vote for some other candidate and 5% are not sure. These results, from an analysis of 15,000 Likely Voter interviews conducted by Rasmussen Reports, challenges the conventional wisdom which assumes that strong support for a Libertarian candidate would hurt John McCain.

In June, Rasmussen Reports asked 15,000 Likely Voters if they were fiscally conservative, moderate, or liberal and if they were socially conservative, moderate, or liberal. This created a total of 16 possible combinations (not sure was a fourth option for both questions). However, 87% of voters fit into one of seven combinations. Libertarians, defined as fiscally conservative and socially liberal, are the smallest of these seven combinations.

The largest group, representing 24% of the nation’s voters, are both fiscally and socially conservative. Demographically, these voters generally reflect the population at large except that 85% are White and just 5% African-American. Sixty-seven percent (67%) are Republicans and McCain leads Obama 82% to 13% among these voters.

The next biggest block of voters, representing 20% of all voters, are both fiscally and socially moderate. Forty-nine percent (49%) of these voters are Democrats and 33% are not affiliated with either major party. They are a bit less likely than the population at large to have completed college but demographically reflect the nation in most ways. Obama leads among these voters 59% to 30%.

Fifteen percent (15%) of all voters are fiscally moderate and socially liberal. Fifty-nine percent (59%) of these voters are women and they are more likely than most voters to have completed college and to have attended graduate school. They favor Obama by an 80% to 13% margin.

Two groups of voters each include 10% of the voting population—those who are fiscally conservative and socially moderate along with those who are fiscally moderate and socially conservative. Among the first group, McCain leads 67% to 25%. Among the latter, McCain’s advantage is smaller, 51% to 40%.

Nine percent (9%) of voters are both socially and fiscally liberal. Not surprisingly, Obama dominates among this segment of the electorate and leads McCain by a 91% to 6% margin. These voters tend to have somewhat higher incomes (25% earn at least $100,000 a year) and are a bit younger than the population at large. Fifty-seven percent (57%) are women.

Looked at from a different perspective, 25% of Obama’s support comes from voters who are fiscally moderate and socially liberal. Twenty-four percent (24%) are both fiscally and socially moderate while 17% are fiscally and socially liberal. No other group provides more than 8% of Obama’s support.

Forty-five percent (45%) of McCain supporters are both fiscally and socially conservative, 15% are fiscally conservative and socially moderate, 14% are both fiscally and socially moderate, and 12% are fiscally moderate and socially conservative.

All data in this survey is based upon interviews with 15,000 Likely Voters as part of the Rasmussen Reports daily Presidential Tracking Poll. Premium Members can review crosstabs for the Obama-McCain numbers results. Additional crosstabs are available here and here.