Late last week, President Obama announced a sweeping community-college tuition plan that drew on the usual superlatives. The plan has already been described as a "moon shot" that could universalize the first two years of college and denounced as yet another part of the president's latent socialist agenda. Others have labeled it an unfunded pipe dream.

In its current form, the plan amounts to a meaningful attempt to narrow the education disparities contributing to the nation’s growing socioeconomic inequality. Its White House architects claim that it could help as many as 9 million students attend college and graduate with less debt. It carries a 10-year $60 billion price tag but includes federal and state components, features that may render some Republicans less allergic to the idea.

Still, the Obama plan fails to account for the fact that few community college students actually graduate or ultimately earn a degree elsewhere. In other words, the system on which the Obama plan is built already struggles to produce strong student outcomes.

Current federal data indicates that just 20 percent of students who started community college in 2009 had completed their programs three years later in 2012.

School officials often discount that tally because it doesn’t account for students who stop their studies at one school and then resume them at another. But other damning figures are harder to dispute.

Only about 15 percent of students who start out at a community college earn a bachelor’s degree after six years. And, researchers have found that when students with similar test scores and grades attend community college or a four-year school, the latter are far more likely to earn a degree.

The conventional wisdom that casts community college as a pragmatic, budget-friendly option isn’t accurate at all. Few community college students rack up the necessary course credits after enrolling to move on smoothly and get their bachelor’s degrees. Most enroll, take some combination of credit-granting courses and remedial education schooling, then move between full- and part-time status to accommodate other demands, often switching schools. After all of that, only a fraction complete their programs—and an even small group earn a degree.

To be fair, community colleges and their students often face immense challenges, obstacles that even the White House has on other occasions acknowledged.

Community colleges already serve almost half of the nation’s college students. The majority of black, Latino, and first-generation college students begin degree work in community-college classrooms. The persistent relationship between race, income, and school quality means that large shares of community-college students start higher education after attending K-12 institutions that post the nation’s worst test scores, where classrooms are led by the least-experienced teachers and schools operate in the worst facilities.

As a result, half of all students entering two-year colleges are tested after enrollment and directed to remedial education courses, compared to 20 percent of students at four-year schools. The efficacy of such courses, which ideally help students master the basic high school concepts they need to complete college-level coursework, is the subject of ongoing debate. Still, this much is clear: The courses do not grant college credits that count towards a degree.

The longer a student at any type of college takes to earn a degree, the less likely they are to graduate. Making matters worse, students attending community colleges generally get little to no one-on-one time with counselors or academic advisors who can help them select a major, plot courses, and monitor progress towards a degree—standard practices at most four-year schools. A 2013 Georgetown University study found that selective, four-year schools have anywhere from two to five times the resources for students than do the nation’s open-enrollment community colleges. Yet, since 2012, all students have faced the same 12-semester limit on Pell Grants, a key source of financial aid for the nation’s lowest income students that does not have to be repaid.

Leading researchers, like Thomas Bailey, the director of the Columbia University’s Community College Research Center, have long questioned the tendency of legislators to restrain budgets at community colleges serving students who, in many cases, have already been educationally cheated. So Bailey gave Obama’s community-college plan a mixed review.

"Generally I think it's a positive to bring more attention to community colleges and bring more federal resources to them," Bailey said. "Tuition should not be a barrier to go to college. But this plan, at least as it stands, it does nothing about all the other issues, the childcare and bus fare, the work hours, the real issues people face as they try to go to school and, too often, have to start and stop."

To bolster his case, Bailey pointed out that many of the nation’s lowest-income students can already attend community college for free. Pell Grants this school year cover up to $5,730 in college expenses for the lowest-income students. The average community college costs about $4,000. If Obama’s plan were to be implemented, Bailey would like to see these students attend community college for free and use their Pell Grants for food, shelter, transportation, books, childcare, and other costs that often get in the way of their education. Those economic challenges factor into another little-known American college phenomenon. Since 2010, black, white, and Latino students have enrolled in college at almost the same rate (Asian college enrollment rates outpace all other groups). But significant graduation disparities remain.

Boosting college graduation rates is where the nation’s critical work sits, according to Stan Jones, the president of the nonprofit Complete College America. Jones, who said he supports Obama’s community-college plan, appreciates its clear references to the country’s completion problem. It would cover tuition costs for part- and full-time students with an at least 2.5 GPA who are making actual progress toward a degree. Those stipulations may push both students and colleges to pay closer attention to course planning and academic advising, while encouraging more students to attend school full-time, he said. But, Jones thinks there is more the plan could do.

Right now, federal financial aid officials consider 12 credit hours per semester a full-time student load. These students are eligible for Pell Grants. But any student enrolling in 12 credit hours per semester, or 24 per school year, is automatically on the path to spend three years completing a two-year program. If Obama’s plan moved the full-time benchmark to 15 or more credit hours or provided an incentive to students who enroll in 15 credit hours or more, it would help a bigger share of students complete their academic programs on time, Jones said. Jones also called on Congress to restore Pell Grant funding for summer courses, which was eliminated in 2011. During the summer term many students previously used Pell grants to take the classes that kept them on track in their programs or repeat required courses they previously failed.

At Florida State University, Toby Park studies community colleges and their students. And like Jones and Bailey, he is a big advocate of students taking more classes and working less.

Both conditions seem to boost a student’s odds of completing their program and earning a career certificate or degree, Park has found. But something about that 15-credit threshold seems to put students in a different mind frame, he said. They become students who work on the side, rather than people who are workers first and students second. National student data shows that the more hours students devote each week to jobs the slower their school progress and the less likely they are to graduate. "Working your way through college" is another popular notion that's an exception among students rather than the rule, Park said.

"It may be psychological, but somehow [work] seems to shift the student’s focus," Park said. "So, I’d really like to see this program address that, even if it means, in the short term, that students have to live on less. Somehow, we need to get more students to take more classes, to focus primarily on school. Really, tuition is only a small part of the problem."