"It's taking place behind closed doors, where it's much more dangerous. It's unsupervised," he said. "It's out of step with social reality."

Instead, he argues, colleges should be given the chance to educate students on how to drink responsibly, within campus boundaries and out in the open.

In 2008 McCardell recruited more than 130 college presidents to sign the Amethyst Initiative, which pushed for a new federal transportation bill that wouldn't penalize states for setting drinking ages under 21. He said he and other college presidents were set to testify before Congress that fall when the economy tanked and legislators' priorities turned elsewhere.

"We missed our moment," he said.

Lawmakers in a handful of states have proposed lowering the drinking age from 21 to 18, but none have gained traction so far.

Experts say lowering the drinking age remains a tough sell to politicians worried about re-election. A 2007 Gallup poll found that 77 percent of Americans opposed lowering the drinking age in all states to 18.

"There isn't much appetite to change something that appears to be working," said Martinic of ICAP. "It's not a very popular issue and it could potentially be damaging to a politician to advocate for a lower age, because nobody wants more traffic accidents. It's pretty much a no go."

But McCardell is not giving up. He believes legal limits for drinking should be set by the states, not the federal government.

And he proposes that American teens be eligible for an alcohol permit -- not unlike a driver's license -- upon turning 18, graduating from high school and completing an alcohol-education course. They would need the permit to buy beer, wine or liquor, and the state could revoke the permit for those convicted of alcohol-related offenses such as drunken driving.