As Republicans have become more effective at smearing honorable Democrats, from McGovern and Dukakis to Kerry and (they hope) Obama, they've spun off some operatives who are more genteel and circumspect, but no less lethal.

These GOP fellow-travellers loathe liberal Democrats as deeply as do Karl Rove and Fox News. But they're too intelligent and self-regarding not to feel embarrassed by their own side's tactics and even by John McCain, who may not be stable or competent enough to be President.

What to do? It depends on how perverse a genteel Republican operative really is. One of them has become so perverse that he reminds me of Vladimir Posner, a smooth, American-born Soviet apologist who popped up on American TV in the 1970s. Posner sidled up solicitously to wavering moderates and liberals and offered, in a folksy American idiom, his understanding, good fellowship, and sage advice at the dawn of a post-ideological era whose solutions lay beyond the stale paranoia about Communist totalitarianism.

Now, Posner's GOP double similarly heralds a trans-partisan, post-ideological age, but, like Posner, he's really working not to advance it but to soften up wavering liberals for the kill. This takes a special perversity. Look closely at David Brooks, the Posner of a sclerotic Republican regime he ought to have outgown and of a neoconservative foreign policy I doubt he'll ever give up.

On PBS, NPR, and in his New York Times column, Brooks gestures toward reconciliation, but only to soften up his targets. In 2004, Brooks seemed solicitous toward John Kerry during the party's convention in Boston -- where, you'll recall, Ted Kennedy and Barack Obama gave terrific speeches. But by September, Brooks had shifted to a genteel but gleeful Swift-boating of Kerry in the New York Times on behalf of George W. Bush.

This year, with Obama, Brooks' stroke-and-slam game won't be so easy, because Republicans are more thoroughly discredited and Obama is harder for someone of Brooks' caliber to dismiss. He's looking a bit desperate up there in PBS' Denver skybox with Jim Lehrer and Mark Shields.

But he still has a card up his sleeve, and he'll play it at the first small sign of Clintonista perfidy on the floor this evening. The card reads, "All would be well with the Republic if only these loathesome, left-liberal Democrats would stop destroying the Democratic Party I once admired and might even have joined."

All would be well, in other words, if only the authentic Al Gore had been saved from Naomi Wolf et al, and the authentic John Kerry had been rescued from endless lines of Volvo-driving consultants peddling their "message" strategies, and if only the authentic Ned Lamont had shaken off netroots practitioners of what Brooks called a "Sunni-Shiite style of politics," whose "flamers... tell themselves their enemies are so vicious they have to be vicious, too." And all could be well now, if only the authentic Obama will keep on rebuffing "Santa Monica Machiavellis" who want him to become a Michael Moore or a Michael Dukakis or something else that isn't himself.

Just this morning, Brooks warned, "The Democrats are in danger of doing to Obama what they did to their last two nominees [Gore and Kerry]: burying authentic individuals under a layer of prefab themes."

Really? Here was Brooks on the "authentic" Kerry in September, 2004, in a Homeric denunciation of Kerry's campaign: "Immense is the army of Michelangelos trying to sculpture the melted marshmallow of Kerry's core. .... And tumultuous is the cry of the strategists, and loud are the furies of the campaign, but in the center there is a silence. For in the beginning all was vacuum and a void..."

This year, similarly, Brooks is giving us not only Obama the "authentic" political leader but also Obama the con man: Just this morning he informed us that when Obama's campaign was stagnant a year ago and liberal advice-givers converged, the authentic Obama heroically "shut them out. He turned his back on the universe of geniuses and stayed true to his core identity.... At the core, Obama's best message has always been this: He is unconnected with the tired old fights that constrict our politics. He is in tune with a new era..... He... is authentically the sort of person who emerges in a multicultural, globalized age. He is therefore naturally in step with the problems that will confront us in the years to come."

Wonderful! But here was Brooks only two months ago on Obama -- a characterization you can be sure he'll give us again this fall: Obama, he wrote in June, "is the most split-personality politician in the country today. On the one hand, there is Dr. Barack, the high-minded, Niebuhr-quoting speechifier who spent this past winter thrilling the Scarlett Johansson set and feeling the fierce urgency of now. But then on the other side, there's Fast Eddie Obama, the promise-breaking, tough-minded Chicago pol who'd throw you under the truck for votes."

The column tells how Fast Edddie threw the Rev Wright, campaign finance reform, and other hard legislative work under the truck even after proclaiming his dedication to all three. Can this be the same Obama who, "true to his own identity," as Brooks puts it, has always been "unconnected with the tired old fights that constrict our politics." ?

I don't know about you, but I find myself wondering about Brooks' own identity, until I recall how closely his "core" resembles that of Vladimir Posner. Watch him tonight, with that slit-eating grin, in the PBS sky box with Jim Lehrer and Mark Shields, oozing solicitude for the ideal Democratic Party the Clintonistas are destroying, to his righteous sorrow... and barely repressed glee.

The only thing constant in this constant shifting of veils of concern for the "authenticitity" of the candidate he'll eviscerate on McCain's behalf in September is Brooks' unquenchable hatred of those he conceives to be left-liberals. Any actual candidate -- Gore, Kerry, Obama -- is merely a proxy in Brooks' own campaign against these liberals. He will portray the candidate as their victim, or collaborator -- whatever suits his need to defeat the Democratic Party which he remains convinced is the left-liberals' captive.

Brooks, August, 2008: "And when Democrats are nervous, all the Santa Monica Machiavellis emerge from their fund-raisers offering words of wisdom. And the subtext of the advice being offered this year is that Barack Obama should really be someone else."

September, 2004: ".....so long was the line of approaching Volvos that it was visible from outer space. Yet still the message was not honed. King Kerry still did equivocate, hedge and reverse. Of flip-flops there were more than a few. He still did Velcro his principles upon the cathedral door, and change them by the hour."

Talk about changing by the hour: Is there anything constant in Brooks beyond his hatred of left liberals? "I have to admit, I'm ambivalent watching all this," he wrote as he described "Fast Eddie" ditching public campaign finance. "On the one hand, Obama did sell out the primary cause of his professional life, all for a tiny political advantage. If he'll sell that out, what won't he sell out? On the other hand, global affairs ain't beanbag. If we're going to have a president who is going to go toe to toe with the likes of Vladimir Putin, maybe it is better that he should have a ruthlessly opportunist Fast Eddie Obama lurking inside."

There is the constant core beneath Brooks' shifting veils, guile and darts: What is most authentic in him is his dark, neo-con intimation of a world of Putins, a world too hard and cruel for those loathesome left-liberals, a world in which one must be even more ruthlessly opportunist than Fast Eddie or Vladimir Posner or even his mirror image, "Darting David" Brooks.

Republicans say they know how dark and cruel the world is, but they have disappointed Brooks because they're not perverse enough to grapple with it, except for a few people around Dick Cheney, at least one of whom has been among Brooks' friends: Most national-security-state Republicans, though, are, like George W. Bush, too rigid to be cleverly lethal; or, like McCain, they're not quite stable enough to pull it off.

That leaves Brooks in a pickle, unlike in 2004. Obama, he acknowledges, is a twenty-first century man who understands that, however dark and cruel the world, it is also too multi-polar to be tamed by the national-security grand strategy and mindset of a Bush or McCain.

Brooks also acknowledges that Obama sees beyond a "free market" system and ideology that have become more a danger than a boon to developed nations themselves. And Brooks knows that Obama isn't underinformed and impulsive or even explosive, as McCain may be.

Yet Brooks isn't sure he can trust Obama to be as ruthless with a Putin as McCain seems willing to be. So, should Brooks risk being ruthless but reckless with McCain, or shrewd and flexible with Obama? As the duplicitous neo-con in him struggles against the man who'd dearly like to be better than a Vladimir Posner of the right, you can see him flailing in that skybox, trapped playing the conservative to Shields' liberal.

[News flash: Sure enough, no sooner had Bill Clinton finished telling the Democratic convention that the world admires "the power of our example more than the example of our power," virtually the first words out of "Vladimir Posner" Brooks' mouth in the skybox were, "I'm not so sure that Vladimir Putin admires the power of our example."]

Brooks will keep trying to soften up liberals for the kill in November, using duplicitous tactics like the following supposedly enlightened standards he claims he'll apply to the Democratic convention this week:

"I'll put a plus down every time a speaker says that McCain is a good man who happens to be out of step with the times. I'll put a plus down every time a speaker says that a multipolar world demands a softer international touch. I'll put a plus down when a speaker says the old free market policies worked fine in the 20th century, but no longer seem to be working today. These are arguments that reinforce Obama's identity as a 21st-century man."

These are also arguments Brooks will shred in the fall as Republicans promise to face down Putin and the Taliban in Pakistan and Afghanistan and to stay the course in Iraq. Or will he? A lot depends on how embarrassing McCain becomes and on how ugly other Republicans become in supporting him.

Brooks has a strong, neo-con stomach for that. But, who knows? Maybe some wise emissary of Obama will whisper in Brooks' ear that it's time to give up the game and to back a tough, forward-looking Democratic administration over a leaky Republican vessel that's wormy with neo-con scheming.