When we last saw Elle Woods (Reese Witherspoon), the indefatigable striver of Legally Blonde 2: Red, White & Blonde, she had graduated from Harvard Law School and gotten her first client off a murder rap, glimpsing clues that no one else could see in such details as perms and Prada shoes. More than that, she'd faced down a world that didn't believe a blonde could own any dimension but blondness. That world, ironically, would appear to include ''LB2'' screenwriter Kate Kondell (in her debut effort) and director Charles Herman-Wurmfeld (''Kissing Jessica Stein''), who have taken a witty and knowing cartoon and turned it into even more of a cartoon.
Elle, who arrives in Washington, D.C., to lobby for legislation to ban animal testing for cosmetics (she's out to rescue the mother of Bruiser, her beloved Chihuahua), now struts around in a pink suit and pillbox hat dispensing peppy bromides like a cross between Shirley Temple and the Energizer Bunny. In her ultra-blond moxie, she's become a bona fide Miss America princess, in endless thrall to her cosmetics and accessories, brimming over with chatter like ''I had no idea I could be this happy without accruing credit-card debt!''
Bits of this are funny -- and true, in their way, to the first film's spirit. The moment when Elle tries to cheer up the glum nerds in her Washington legal office with her Pollyannaish Snap Cup, filled with saccharine affirmations from one's coworkers, may not match the daffy high of her ''bend and snap!'' pick-me-up routine in ''Legally Blonde,'' but it'll do. Elle parades her peachy presence before the somber Committee on Energy and Commerce (''This is just like on C-SPAN, except I'm not bored!'') and gets a door slammed in her face as she tries to lobby a senator with a pop-up chart.
What's missing, however, is the undercurrent of vulnerability that gave Witherspoon's original performance its adorable, winsome glow. She's still a marvel of sweetly sparky enthusiasm, but ''Legally Blonde'' was the movie that ushered her into stardom, and the leap in confidence she has taken in the two years since now renders Elle altogether too impervious. At once brasher and more frivolous, she's a lot less compelling fighting for the welfare of lab-test animals than she was crusading for her own dignity.