The Times pretty much nails it:
Prominent evolutionary biologists, like the author and Oxford professor Richard Dawkins — accurately identified on screen as an “atheist” — are provided solely to construct, in cleverly edited slices, an inevitable connection between Darwinism and godlessness. Blithely ignoring the vital distinction between social and scientific Darwinism, the film links evolution theory to fascism (as well as abortion, euthanasia and eugenics), shamelessly invoking the Holocaust with black-and-white film of Nazi gas chambers and mass graves.
Every few minutes familiar — and ideologically unrelated — images interrupt the talking heads: a fist-shaking Nikita S. Khrushchev; Charlton Heston being subdued by a water hose in “Planet of the Apes.” This is not argument, it’s circus, a distraction from the film’s contempt for precision and intellectual rigor. This goes further than a willful misunderstanding of the scientific method. The film suggests, for example, that Dr. Sternberg lost his job at the Smithsonian’s National Museum of Natural History because of intellectual discrimination but neglects to inform us that he was actually not an employee but rather an unpaid research associate who had completed his three-year term.
Mixing physical apples and metaphysical oranges at every turn “Expelled” is an unprincipled propaganda piece that insults believers and nonbelievers alike. In its fudging, eliding and refusal to define terms, the movie proves that the only expulsion here is of reason itself.
Thanks to the producers, the conflation of Christianity with dishonesty and sleaze will continue for a long time. Thanks, guys.