Washington (CNN) - Americans appear to view marijuana in a class by itself.
According to a new national poll, marijuana is not as wicked as other illegal drugs like heroin and cocaine, and much less dangerous than legal substances like alcohol and tobacco.
That's one reason why a CNN/ORC International survey indicates that support for legalizing marijuana is soaring, and why that same support does not extend to hard drugs.
A CNN/ORC poll released Monday showed that 55% of all Americans think that the use of marijuana should be legal - a solid majority and more than triple the 16% who said the same thing a quarter century ago. But according to numbers released Tuesday, the percentage is nowhere near as high as the 81% who say alcohol should remain legal or the 71% who believe that tobacco use is OK.
Yet, despite the high numbers who think alcohol and tobacco should be legal, nearly three-quarters say that booze is more dangerous than pot, and more than six in 10 think the same thing about cigarettes and cigars.
The numbers on alcohol and marijuana is a major switch from four decades ago, when Americans were split on which was more dangerous to use.
"The logical conclusion: Many Americans believe that if more dangerous substances like alcohol and tobacco are legal, marijuana should be, too," CNN Polling Director Keating Holland said.
What about harder drugs like cocaine, heroin, or methamphetamines, better known as crystal meth?
According to the poll, Americans almost unanimously agree that those substances should remain illegal. Only 4% say that cocaine and heroin should be legalized; only 3% feel that way about methamphetamines.
There is a notable moral dimension to how Americans feel about harder drugs that does not apply to marijuana or alcohol: Roughly eight in 10 questioned in the poll say that using heroin or cocaine is morally wrong. As CNN reported on Monday, only 35% feel that way about marijuana, about half the number who felt that way in the 1980s. And only 16% say that drinking alcohol is morally wrong, down from 38% a quarter century ago.
"Once again, opinions on marijuana seem to represent a halfway point between generally accepted substances like alcohol and widely reviled substances like cocaine and heroin," Holland said.
The poll was conducted for CNN by ORC International from January 3 to 5, with 1,010 adults nationwide questioned by telephone. The survey's overall sampling error is plus or minus three percentage points.
CNN Political Editor Paul Steinhauser contributed to this report