The continuing fascination with Richard Nixon, complexly flawed and self-destructive on a near-Shakespearean scale, is on display at the Benedum this week. "Frost/Nixon" is Peter Morgan's recent play about the skirmishing before and during the 1977 interviews with British TV host David Frost in which Nixon admitted in a grudging, limited way to his culpability in the abuses of power known as Watergate.

Yes, it's a play, not a docudrama, but its power certainly draws on its documentary atmosphere, our sense that we are watching a factual debate about events that much of the audience lived through in real time.

That's partly an illusion, because much of the play is Morgan's invention, however plausible. Presumably the short excerpts from the televised interview itself are accurate, but most of the play is backstage, late-night, monologue, narration, strategizing (especially among Frost's team of advisers), etc. It's testimony to the fascination of the subject and the competence of the play that a large audience watched attentively Tuesday as the deal was negotiated and the combat joined.

That attentiveness may have had something to do with the focus necessary to hear clearly, since the production refuses to use body mikes in the Benedum. My own hearing is about average, my seat was good, and I've seen the play before, but there were still passages I couldn't hear as clearly as I wanted. The Benedum's 2,800-seat size seriously dilutes the impact "Frost/Nixon" had in its 1,100-seat Broadway theater.

The refusal of mikes is principled, a disavowal of artifice in favor of immediacy and the real thing -- again, that documentary implication. So it is at least ironic that "Frost/Nixon" scores its greatest effect with a TV image: a giant close-up of Nixon's crumbling face, ultimate admission of his cover-up guilt, projected on the screen above the stage.

Setting aside the scenes of preparatory strategy and the progress of the interview tapings (Nixon ahead on points but Frost scoring a last-round TKO), "Frost/Nixon" is primarily about its two combatants.

Frost is portrayed as a genial but strangely vacant TV host; hardly a journalist, he's a creature of his medium. Alan Cox gives him sunny, even ingenuous charm, but for the most, we have to intuit what other than ambition drives him to risk money and credibility on a project that might wreck his career.

But the heart of the play is Nixon, portrayed by Stacy Keach with public joviality and private obsession. It's a solid, honorable performance, though without the mesmerizing charisma of Frank Langella on Broadway. Yes, it scores with that giant close-up of defeat, but even this stage Nixon remains a man in whom partisans and detractors can see mutually-exclusive truths.

Playwright Morgan's most interesting speculations are about the personal parallels between Frost and Nixon and about Nixon's psychic need/fear of self-revelation. This leads to an invented late-night phone call from Nixon that might be Frost's hallucination.

I mainly object to the invention of Frost assistant James Reston Jr.'s 11th-hour discovery of transcript material used to crack Nixon open -- material really uncovered months before. It's a useful trick to juice up the plot, but it falsifies and clouds the issue of Frost's interview strategy.

Nixon's dark fascination is doubtless increased by the shallow imperturbability of our current president, an intellectual dwarf by contrast. It is tempting to see "Frost/Nixon" as a parable of the current administration, which has similarly extended an unnecessary war and ignored constitutional safeguards in the name of presidential power.

But "Frost/Nixon" is slim on historical content -- there's nothing about Nixon's actual Southeast Asian policy. It's more drama than history, more about media than policies or politics. Yes, it suggests a serious debate about the intersection of media, politics and personality. But it would be a shame if its necessarily simplistic history diverted attention from the real thing.

Will that history be further simplified, muddied -- or clarified -- by the impending arrival of "Frost/Nixon," the movie?