If you’re a Democratic primary voter in Ohio, Texas or Pennsylvania, and are still torn between Obama and the Clintons, here’s the best reason I know to throw your support to Obama: Mark McKinnon.

Love him or hate him, there’s general agreement that McKinnon — the chief media adviser and strategist for presumptive Republican nominee John McCain – is a genius at what he does. So it’s no surprise that, even though it’s relatively old ‘news,’ word that McKinnon will stop working for McCain if Obama is the Democratic nominee has been freshly burning up cyberspace of late.

Citing his admiration for the Illinois senator, McKinnon says he cannot face being part of a campaign that “would inevitably be attacking” Obama. “I have met Barack Obama. I have read his book. I like him a great deal, he told National Public Radio. “I disagree with him on very fundamental issues but it would be uncomfortable for me and it would be bad for the McCain campaign.”

But who is Mark McKinnon — and why does his unusual stance matter so much? For starters, because as the chief media adviser and strategist for the Bush-Cheney campaigns, he arguably deserves more credit (or blame, depending on your politics!) than any other individual for George Bush being in the White House. Anyone who can get George Bush elected President of the United States twice (and Governor of Texas before that) is a danger to Democrats everywhere, and the fact that McKinnon will withdraw his services from McCain in the event of an Obama nomination should be music to the ears of anyone who wants to see an end to our long national nightmare—aka the Bush Administration and its possible successors.

I first met McKinnon in 2004, while covering the presidential media campaigns for the television industry journal Broadcasting & Cable. He returned my first call immediately — unlike his inept Democratic counterparts, who failed to return fourteen calls and then hung up when I finally got through. After telling me to check in with presidential counselor Dan Bartlett (who also promptly returned the call) McKinnon then invited me to spend a day at the Bush/Cheney campaign offices in suburban Virginia.

Upon arrival, I asked McKinnon what his media plan for the campaign against John Kerry would be. To my surprise, instead of dodging, filibustering or ignoring the question, he answered in a forthright manner. “We plan to spend sixty million dollars in the next ninety days defining John Kerry before he can define himself,” McKinnon told me.

“How are you going to define him?” I shot back.

“As a flip-flopping liberal who’s wrong on defense,” McKinnon replied.

I then watched in amazement over the next three months as he proceeded to do exactly that. Within weeks of our conversation, ordinary people all over the country suddenly began saying that they had doubts about Kerry – particularly, they parroted, because he seemed like such a “flip-flopper.” The mainstream media lapdogs soon followed suit.

Kerry never recovered from the preemptive assault on his authenticity, which was later reinforced by images of windsurfing and clips of him saying, “I actually did vote for the $87 billion before I voted against it.” Game, set and match to the Republican side.

So who then is Mark McKinnon? And why is the man who first elected George W. Bush, and later rescued John McCain from the land of the politically dead and then took him to the brink of the nomination, saying he won’t help McCain in November if Obama is the Democratic candidate? The high-school dropout, onetime staff songwriter for Kris Kristofferson, formerly Democratic political operative who once denounced Karl Rove and friend of such liberal heavyweights as onetime Clinton advisers Paul Begala and James Carville seems an unlikely choice as President Bush’s or candidate McCain’s campaign media director. But politics is first and foremost about winning — and McKinnon’s candidates win.

“It all started with Hank the Hallucination,” McKinnon recalls. “Hank and Paul Begala are the reasons I got into politics.” Hank, an illustrated comic strip character in the Daily Texan, the student newspaper McKinnon edited, ran with his backing against Begala in a 1982 contest for student government president at the University of Texas in Austin — and won. “I was a bit of an anarchist in those days,” McKinnon recalls.

Hank was the first in a long series of winning candidates that McKinnon has backed. “I was a volunteer for Lloyd Doggett in my first real campaign in 1983,” he says. “Carville was the campaign manager, and Begala was in the upper echelon. He brought me out of the basement.”

McKinnon continued to work in winning Texas Democratic campaigns after that, helping to elect Ann Richards as governor in 1990 and Bob Lanier as mayor of Houston in 1991, among others. But by 1996, as he explained in a Texas Monthly essay called “The Spin Doctor is Out,” he had burned out on partisan politics and “last-minute attack and response ads.” Instead he planned to concentrate on corporate clients and public affairs, such as a successful 1997 effort to preserve affirmative action.

Then he fell in love, and everything changed. As he famously told a reporter, McKinnon saw Bush at a party and had the feeling that a man has “when he’s at a party with his wife and sees a beautiful woman across the room.”

The object of his newfound affection was George W. Bush, then governor of Texas. “It is unusual” for a conservative Republican politician and a liberal Democrat media maven to hook up, McKinnon admits. “The nexus was [Democratic] Lieutenant Governor Bob Bullock, who was my mentor.” McKinnon and Bush became jogging partners and fast friends. Soon Bush began courting McKinnon professionally as well.

“Even as Governor, President Bush was famously skeptical about political consultants,” McKinnon says. “And at the time, all the typical Republican hired guns were circling. Hiring me was certainly a counter-intuitive move. I think he liked the idea that I wasn’t looking to work in politics anymore.”

In the end, McKinnon says, he decided to work for Bush “out of respect, loyalty and friendship — which as you know are qualities that are very important to the Bush culture.” Those feelings were reciprocated by Bush, who put McKinnon in charge of two of the most well financed media operations in history.

The strategies McKinnon employed in the past decade may seem awfully negative for a man who says, “Negativity drove me out of politics in the mid-Nineties.” (After all, McKinnon was the architect of the ads that trashed John McCain in South Carolina and beyond in 2000, ensuring a Bush nomination.) But McKinnon says it isn’t so.

“It’s not negative to define John Kerry. We’re not doing attack ads, we’re doing strong contrast ads,” he told me four year ago. “That’s legitimate, not negative. We aren’t saying Kerry is ‘Weak on Defense,’ we’re saying he’s ‘Wrong on Defense.’ There’s a big difference.”

As I wrote at the time, “The war of words matters a lot, and while McKinnon concedes that the Bush campaign is busy testing them in focus groups, he offers no details. Still, it’s clear he is attempting to position the president as a ’steady’ leader and Kerry as a ‘flip-flopper’ who changes positions often for political expediency. If the words work, they will be repeated over and over as part of that ‘coordinated blitz’ aimed at defining Kerry as ‘indecisive and lacking conviction.’”

Despite the fierce hatred he has engendered in some of his former friends, McKinnon generally remains an approachable and affable figure. Even Begala – who eventually did become student body president by winning a runoff between the “two top humans” after Hank the Hallucination was gunned down — extols him. “I love him!” Begala told me. “He’s a wonderful, terrific guy.”

Even though he went over to the Dark Side?

“It’s a free country. Sure, he was way to the left of me in college, and now he’s way to the right,” Begala responded. “But hey — James Carville goes home every night and goes to bed with Mary Matalin… Mark has changed his life, but I don’t believe he had a conservative epiphany.

“I believe him when he says this is based on a deep and personal love of George Bush. But this is not a race for student government president,” Begala concluded. “Still, if Bush is ruining the country, I say let’s attack the organ grinder and not the monkey.”

“I haven’t taken as many shots as I thought I would,” McKinnon conceded at the time. “Probably because Begala blessed me.”

Would he describe himself as a Republican?

“Let’s just say I’m a man of evolution,” he responded with a grin.

His many critics now contend that, far from “evolving,” McKinnon is just an opportunistic turncoat, a lustful chameleon, a bizarre sellout… and worse. In any event, now it’s time for another hallucinatory campaign, and McKinnon is once again in the thick of it.

Just ask John McCain—or Barack Obama, for that matter!