One of the real heroes of "Grass," Ron Mann's punchy and enjoyable new
documentary on the history of marijuana in the United States during the 20th
century, is Mayor Fiorello H. La Guardia of New York. While Harry J.
Anslinger, the federal government's first drug czar, spent his career
looking for a way to pin as many evils on marijuana as he could, and
punishing those who disagreed with him, La Guardia calmly commissioned a
study on marijuana use. The study concluded that "the sociological,
psychological and medical ills commonly attributed to marijuana have been
exaggerated insofar as the City of New York is concerned." It's no wonder
that an airport was named after him.

"Grass," which opens today at the Film Forum, begins with the adoption of
anti-marijuana laws as part of an institutionalized racism toward Mexicans
in the Southwest early in the century.

Eventually, the film says, the laws were a bludgeon against anyone who
threatened the status quo: the young during the 1960's, and before that,
entertainers like Robert Mitchum and Gene Krupa. "Grass" misses out by not
including a clip from the "The Gene Krupa Story," a middlebrow attempt to
depict the lurid world of jazz in 1959. "Grass" offers meticulous sound
design, and some snappy graphics put together by the film's art director,
Paul Mavrides, who once toiled in the underground comics world.

There's a brief, unidentified cameo by the Fabulous Furry Freak Brothers,
the cannabis heroes of the comics whose adventures Mr. Mavrides helped
depict.

The picture is broken up into sections recounting the varying official takes
on the effects of marijuana, like its leading to insanity, heroin abuse,
Communism and finally, indolence.

The movie doesn't focus exclusively on the gaunt, wide-eyed stereotype of
the pot addict, though it does use that image to score a number of laughs.

There are views of maniacal pot smokers like those that appeared in the
1950's publications of E.C. Comics, which figured prominently in "Comic Book
Confidential," one of Mr. Mann's early films. Like "Comic Book Confidential"
and Mr. Mann's documentary "Twist," "Grass" fixes on a frightened mainstream
reaction to a cultural phenomenon and a overzealous, singleminded crusader.
. Anslinger lends himself to the Javert treatment; it doesn't help that he,
and most of the other law enforcement officers shown here, all age to look
like J. Edgar Hoover. The film is narrated by the celebrity weed aficionado
Woody Harrelson, whose very name in the credits will ensure a laugh from
audiences. But "Grass" doesn't just limit itself to easy potshots like
showing scenes from the infamous "Reefer Madness" (1936), although it does
use a number of the propaganda films that sought to frighten the naive.

In those overwrought little dramatizations, marijuana smokers were driven to
rape, violence and in the 1960's, even to the shocking implication of
miscegenation. The film also leaps ahead to the days of "Just Say No," just
to show that the swing of the anti-pot pendulum in the other direction was
useless. "Grass" is a huge step forward in cool and confidence for Mr. Mann,
who makes his case here with seductive, fun Pop Art graphics and very smart
use of music and clips: Cab Calloway and other jazz hipsters are among those
seen extolling the virtues of marijuana, though Rick James, whose "Busting
Out" is heard on the soundtrack, probably isn't exactly the best choice for
a pro-pot poster child.

President Richard M. Nixon, to show his tough-on-crime stance, is seen
waging his own war against pot and deputizing another unlikely drug warrior,
Elvis Presley.

With its pointed narrative, the film makes its case with a minimum of
pushiness and a subtle nod to its crowd. "Grass" begins and ends with the
credits, as if assuming its target audience might suffer short-term memory
loss for some reason.