Most community college presidents support free community college, but they’re skeptical that it will be a national phenomenon.

A survey from Gallup and Inside Higher Ed found that 62 percent of presidents support the free initiative, but only 35 percent agree that free programs “will be adopted in at least one-third of states within the next five years.”

Despite Tennessee’s foray into free community college, along with Oregon and Kentucky developing programs, most of the 220 community college presidents surveyed don’t expect that trend to become the standard.

Pessimism and political reality could drive that gap. Making a campaign pledge to make college free is one thing, but funding it is another. That has played out among the Democratic presidential candidates, as Hillary Clinton attacked Bernie Sanders over his college plan because it relied on states increasing their funding for higher education. States have lowered their relative levels of funding for colleges since the recession, and Republican governors could act as a roadblock to Sanders’s college plan. Clinton’s plan, too, relies on greater state funding for colleges. Community college presidents might recognize that, even though they agree with the goal of free community college, the political climate could dampen the chances of it happening.

Some of that is an ideological disagreement with making community college free, too. Community college tuition is already much lower than the average four-year public college. Community colleges charged $2,713 for tuition in 2010-11, according to the College Board, whereas in-state tuition for a public four-year college was $7,605. Free community college grabs attention, but the financial pressure of community college comes from paying rent, affording textbooks, and the culture clash that poor students face. In that respect, free community college can distract from other financial burdens that prevent students from completing a degree.

If free community college gains support in more states, though, presidents could see a boon in enrollment. “The majority of community college presidents, 58 percent, report that their enrollment for the 2015-16 academic year is lower than that of the previous academic year,” the survey found, and only 21 percent of presidents reported an enrollment increase. With free colleges come more students, as Tennessee found in their first year of free community college.

That could reverse the enrollment decline, which would benefit community college presidents, but the benefits are less clear for students themselves. Most presidents cited a growing economy to explain the enrollment decline, and graduation rates for community colleges remain low. Transfers to four-year colleges and other factors can influence that, but the average remains that less than 30 percent of students earn an associate degree within two to four years. Before free community college catches on, the public needs a clear picture of how community colleges benefit the students who enroll.