James Van Der Beek and Dylan McDermott stand taller in the saddle than the heroes of the last few pretty-boy Westerns. Van Der Beek, who knows not to push his angular handsomeness, has the makings of a true movie star (he needs to act a little more gruff and a little less sweet), and McDermott looks just sinister enough in black to make you wonder whether his Texas Rangers captain has uglier things on his mind than justice. For all the appeal of its stars, though, this is one bland and cheesy Tex-Mex burrito of a movie. The Rangers are an army of noble enforcers -- or are they reckless vigilantes devising their own laws? The conflict gets thrown away before it has even had a chance to come to a head. ''Texas Rangers'' is full of thundering-hooves montages meant to suggest that there's a lot more going on than there actually is. What's going on is: hunks on horsies.