Loan debt is now as much a part of the college experience as frat parties and all-night study sessions, but it wasn’t always so. In fact, in the 1980s, tuition made up less than a quarter of funding for higher education. With state and federal money paying the bulk of the costs, students graduated with minimal debt, if any at all.

That has changed in the last 30-plus years, as public colleges and universities around the country began relying less and less on public funding, and more on tuition and fees from students. The trend only accelerated during the Great Recession, even as more people left the sour job market to seek degrees, forcing schools to either raise tuition or cut valuable programs.

As a system created to provide access to higher education for everyone, regardless of economic status, that is unacceptable, and unsustainable.

The shift in funding, taking place through less than four decades, is remarkable.

According to the State Higher Education Executive Officers Association, tuition accounted for less than 24 percent of higher education funding nationwide in 1988. By the start of the Great Recession in 2008, that number had risen to more than 35 percent. Now, it is 47 percent.

In Maine, the same has happened, only worse. In 1988, the average student in the University of Maine System paid less than a quarter of the total sticker price of their education. By 2008, however, students were picking up half the tab, and by 2013, almost 58 percent of higher education funding came from students.

This increasing reliance on tuition has helped push the cost of state universities and colleges up 230 percent since 1980. Meanwhile, programs such as Pell grants meant to help low-income students afford college have failed to keep up; Pell grants once covered 70 percent of the costs of going to a public institution, but now only cover 30 percent.

And through this same time period, real income, especially at lower levels, has remained almost unwaveringly static.

So in the same time that a college degree has grown increasingly critical to one’s future employment and earnings, it also has become more out of reach for low- and middle-income families.

There was some hope in the last fiscal year, when state funding for higher education ticked up slightly after four years of decreases following the 2008 crash. In Maine, last year brought a slight increase in state funding coupled with a small decrease in tuition, when adjusted for inflation.

But it will take continued investment to reverse a now decades-long trend that has weakened public colleges and universities, left many graduates with stifling debt, and kept others from pursuing higher education altogether. If public higher education is going to remain a great instrument for building the middle class, that has to change.