Is there any role Johnny Depp cannot make his own?</p><p>Last seen as a singing Victorian barber and serial killer in &ldquo;Sweeney Todd,&rdquo; the human chameleon has effortlessly mutated into Depression-era desperado John Dillinger for director Michael Mann&rsquo;s &ldquo;Public Enemies.&rdquo;</p><p>Charismatic, funny, dangerous &hellip; Depp blends derring-do, cocky self-confidence, sly sexuality and a bit of madness to give us a crook we can cheer for.</p><p>From a distance of more than seven decades it&rsquo;s difficult to imagine a time when a bank robber was considered by millions to be a national hero. Depp helps us understand why.</p><p>He is the tireless motor that drives the film and is the main reason it succeeds. Though well-mounted, &ldquo;Public Enemies&rdquo; is a fairly generic crime drama filled with underdeveloped characters. Without Depp&rsquo;s weight, the film would be flimsy. With him it&rsquo;s a heady romp through a legendary era of America&rsquo;s criminal past.</p><p>In adapting Bryan Burrough&rsquo;s sprawling nonfiction best-seller. Mann and co-writers Ronan Bennett and Ann Biderman jump on two story lines. First there&rsquo;s the relationship between Dillinger and nightclub hatcheck girl Billie Frechette (Oscar-winner Marion Cotillard), a doomed Bonnie-and-Clyde romance fueled by adventure, sex and a recklessness born of fatalism.</p><p>Then there are the G-men &mdash; top federal cop J. Edgar Hoover (Billy Crudup) and especially agent Melvin Purvis (Christian Bale), who are determined to bring down the working-class gangsters who shot up the Midwest in the early &rsquo;30s.</p><p>Depp&rsquo;s tasty performance views Dillinger as a folk hero in the making. The son of a poor Indiana farmer, this criminal quickly learned the value of publicity. He even developed a trademark &mdash; once in a bank, he&rsquo;d loudly introduce himself and gracefully vault over the teller&rsquo;s counter, tommy-gun in hand. People remember an entrance like that.</p><p>Dillinger would clean out the vault but leave untouched the cash held by individual customers, saying he was there for the bank&rsquo;s money, not theirs. At a time when many had seen their savings wiped out in bank collapses, this was sweet revenge.</p><p>While some members of his gang &mdash; particularly the psychopathic Baby Face Nelson (Stephen Graham) &mdash; were crazed killers, Dillinger seems to have shown restraint. It&rsquo;s never been proven that a bullet fired by him killed anyone.</p><p>And he had a devil-may-care attitude that many found intoxicating. Told by a colleague that he should stop going to nightclubs and baseball games, Dillinger answered, &ldquo;We&rsquo;re having too good a time today. We ain&rsquo;t thinkin&rsquo; about tomorrow.&rdquo;</p><p>Mann&rsquo;s film takes some liberties, particularly with time lines. (The movie opens with Agent Purvis gunning down Pretty Boy Floyd; in reality, Floyd died months after Dillinger, and Purvis wasn&rsquo;t there.)</p><p>But it faithfully re-creates some of the book&rsquo;s most memorable moments, such as Dillinger&rsquo;s daring escape from an Indiana jail using a &ldquo;gun&rdquo; carved from wood and the FBI&rsquo;s wintry nighttime shootout with the gang at a remote Wisconsin resort. </p><p>&ldquo;Public Enemies&rdquo; attempts to establish a sort of personal duel between the taunting, charming crook and Bale&rsquo;s grim, unemotional lawman. But the film&rsquo;s true emotional core lies in the Dillinger/Frechette affair. Cotillard is excellent as the unremarkable young woman who falls hard for the electric excitement radiating from her lover&rsquo;s every pore.