The Ku Klux Klan, for 120 years a symbol of racial and religious bias and terrorism in America, needs no introduction. That's why the documentary, "The Klan: A Legacy of Hate in America," to be shown on Channel 26 tonight at 9, seems out of step with the times.

In the past couple of years, the Klan has gained new visibility. Crosses have been burned from Prince George's to Marin counties. The Klan has marched down numerous Main streets, and may do the same this weekend in Washington. Politicians have run openly as Klansmen. In the last five years, Klan membership has doubled.

And blacks, Jews and Catholics, the principal targets of Klan hatred and violence, are outraged. Surely filmmakers Charles Guggenheim and Werner Schumann, Washington producers with top-notch credits, share the horror of this resurgence. But their half-hour product has the look of a palatable newsreel, and takes a neutral point of view that seems unnecessary.

Even the commercial media, which at times has romanticized the Klan, has managed lately to provide an exciting and informative forum. The raw emotions of a recent Phil Donahue show with Klanswomen revealed the irrationality of contemporary bigotry more than any moment in tonight's program.

The film, narrated by James Whitmore, and financed by the Southern Poverty Law Center, presents a concise history of the Klan, devoting half the footage to familiar scenes of burnings, lynchings, marches, recruitment rallies and leaders from the Reconstruction to the l960s civil rights movement. Included in the remainder of the program are interviews with victims of l980s Klan activity in California and Texas, indicating that the group's targets have spread to Mexican workers and Vietnamese fishermen.

While the scenes of the group's activity are enough evidence of its horror, the film needs to challenge the Klan's ideals more strongly. Fortunately, the Channel 26 broadcast will be followed by a discussion that includes Sheila Banks, host and correspondent for WETA; John Gibson, co-chairman of the Washington-based Coalition for National Unity against the Klan; and Rev. Ernest Gibson, of the Council of Churches of Greater Washington, which might put the show into a stronger context.