Even among people who oppose tuition-free public college, 1 in 4 said that it would be acceptable to offer that benefit to families who earn $50,000 or less, according to the Bankrate survey.
"There is no such things as 'free,'" said Neal McCluskey, director of the libertarian Cato Institute's Center for Educational Freedom. "What students don't pay in tuition for the education from which they benefit, someone else has to pay."
Low-income students receive more help from taxpayers to pay for college than higher-income students, according to a recent analysis by the Brookings Institution.
Whether tuition-free college becomes a reality, state governments are already spending more on public colleges and universities. State support for higher education is up 4.1 percent this year, according to the Center for the Study of Education Policy at Illinois State University.
"The biggest challenge with state funding for higher education is not just increasing it, but making it consistent," said Ben Miller, senior director of post-secondary education at the liberal Center for American Progress Action Fund. State governments tend to support higher education when the economy is strong and cut back when the economy weakens, he said.