Presidential hopeful Sen. Marco Rubio (R-Florida) recently came under criticism for his co-sponsorship of a bill which provided in-state tuition to undocumented immigrants in Florida.

The law was enacted in 2004 when Rubio was in the Florida Statehouse, according to the Huffington Post and Washington Post, and Rubio told ABC’s This Week that he “absolutely” stands by his co-sponsorship of the bill a decade later.

The legislation mandated that undocumented immigrants would only be able to receive in-state college tuition if they had lived in the U.S. for a long time and if they graduated high school with a certain GPA.

“It was very narrowly tailored to high-performing students who found themselves in a situation where they were brought here by their parents when they were five, didn’t even speak another language except English, and therefore couldn’t attend college because they were being charged like they were from out of state,” Rubio explained. “They still had to pay for college, but they paid…what people paid when they lived in Florida.”

The issue of providing any sort of benefits to undocumented immigrants has become a controversial and divisive issue in light of the upcoming presidential election, and it’s almost surprising that it took this long for criticism about Rubio’s involvement in the law to hit headlines.

“We didn’t legalize anybody. That’s the issue here,” Rubio said, while explaining that he still opposes deportation relief and the legalization of undocumented immigrants.

Still, this tuition assistance legislation is pretty substantial; considering that the average public college charged just over $9,000 in the 2014-2015 school year but only for in-state residents, the additional tuition assistance has allowed hundreds of young immigrants to pursue a higher education.

It’s getting more difficult for families living legally in the U.S. to send their kids to college. As the National Journal reported, public college tuition has skyrocketed in recent years for no apparent reason — in 1971, and accounting for inflation today, annual tuition was just $500.

Allowing more young adults to receive a college education would be, according to liberals, the best way to make sure that undocumented immigrants contribute positively to the U.S. economy. Conservatives like Rubio, however, are still trying to justify certain proactive legislation with a hardened stance against immigration.

“I continue to support and have supported and sponsored the largest border surge in American history, 20,000 new border agents, 700 miles of fencing and walls, a mandatory e-verify system, [and] entry-exit tracking system to prevent visa overstays,” said Rubio.