If Democrat John Kerry (Mass.) wants to rise above a perpetual tie with President Bush, he ought to try this theme: “I’ll really be a uniter, not a divider.”

Stealing Bush’s manifestly unfulfilled 2000 promise — and vowing to make good on it — is free advice offered to Kerry by Don Baer, Bill Clinton’s former communications director. He says that Kerry ought to “aim high — way high” to get into the lead against Bush. [IMGCAP(1)]

What Kerry is doing now — blasting Bush relentlessly and misleadingly accusing Bush’s campaign of practicing low-blow politics — clearly is not moving voters, despite a continuing flow of bad news from Iraq and falling presidential approval ratings.

The latest Gallup poll found that Bush’s overall job-approval rating is down to 46 percent, the lowest of his presidency — yet among likely voters, Bush continues to lead Kerry (if only narrowly) by 48 percent to 47 percent.

Baer, now a senior executive at Discovery Communications, told me that “Americans want to be united, especially after 9/11. People are serious now. They crave grown-up leadership. Populist ‘fighting’ isn’t what they want. So Kerry ought to try to foster a new spirit of common purpose.”

In Baer’s view, Kerry ought to point out that Bush repeatedly promised in 2000 to unite the country, but has polarized it instead. Kerry, he says, should vow to repair the breach — by, among other things, promising to form a Cabinet of “the best people in America, regardless of party.”

“His theme ought to be that ‘the problems we face as a country are so big that we can’t approach them divided,’” Baer said. “Just the way he’s promised to reunite with our allies to fight terrorism, he should aim to reunite the country around lofty purposes like keeping America as great in the 21st century as it was in the 20th.”

Implementing such a plan would not necessarily be easy. Adopting the Baer formula — and, hopefully, following through on it — would require abandoning the “50-50” strategy now being followed by both parties.

That strategy assumes that the country is split into equal “red” and “blue” blocs of about 45 percent of voters, and that the way to win is to energize and mobilize your base with hot-button appeals so that close to all of your voters show up at the polls on Election Day. Attention to independents and centrists, under this approach, consists of mere genuflection.

In 2000, President Bush won election — though not the popular vote — by simultaneously mobilizing the “red” base of Southerners, church-goers and married people with children while also touting himself as a “compassionate conservative” who would “restore civility” to political discourse.

The Bush team has largely ignored those ideals in practice. With a few exceptions such as education reform and meeting with Democratic leaders immediately after Sept. 11, 2001, he’s governed largely on a Republicans-only basis. Bush has given short shrift to “compassion” and had no interest in toning down the polarizing effect he has on Democrats.

Democrats, in turn, have gone close to berserk in their hatred for Bush, with presidential candidates — including Kerry — accusing Bush of everything from lying to get the country into war with Iraq to endangering basic American liberties by entrusting Attorney General John Ashcroft with administration of the USA Patriot Act.

It’s become standard practice for the Kerry camp to respond to Bush ads criticizing Kerry’s 20-year voting record on defense by accusing Bush’s “smear machine” of questioning his service in the Vietnam War or his patriotism.

But there’s a problem. I asked the Democratic National Committee’s research department for a list of the worst GOP attacks on Kerry so far. There was not a single instance when a GOP or Bush campaign official mentioned “patriotism” or attacked Kerry’s Vietnam service. The closest to a low blow was made by a Bush supporter, former Vietnam POW and Rep. Sam Johnson (R-Texas), who called Kerry “Hanoi John” for alleging, when he was an anti-war activist, that GIs had committed atrocities in Vietnam.

At the same time, it has been Kerry who’s questioned Bush’s wartime National Guard service — something he vowed he would not do.

And last week, Kerry’s wife Teresa — in an apparent reference to Vice President Cheney and others in the Bush camp who did not serve in the military — said that “to have a couple of people who escaped [the draft] four, five, six times and deferred and deferred and deferred calling [Kerry] anything regarding his service is in and of itself unpatriotic. Unpatriotic.”

Despite significant differences on social issues and economic policy, there also are notable areas of convergence between Kerry and Bush that a “uniting” Kerry could emphasize as a way of depolarizing the debate.

Despite criticizing Bush’s means of entering Iraq, Kerry does not favor abandoning the cause and actually favors adding U.S. troops to bring stability.

Kerry’s economic policy actually involves lowering corporate income-tax rates to help create jobs, and he claims to want to reduce the federal deficit to ensure the solvency of Social Security and Medicare.

Even on health care policy, where Kerry plans to spend 10 times what Bush would to help the uninsured, the two do at least agree on modernizing information technology so that errors can be reduced and health costs cut.

And there is no need for Kerry to come across as a wimp to portray himself as a “uniter.” There is nothing in this strategy that prevents Kerry from campaigning vigorously on policy differences and even questioning Bush’s credibility on issues such as “compassion.”

Baer’s point is that Kerry ought to appeal for — and promise to strive for — national unity and common purpose.

And if there was ever a demonstration of how Americans need to be — and, in fact, are — in the same boat, it was the beheading of Nicholas Berg by Islamic militants shouting “God is Great!”

Berg’s brutal murder was a reminder that, whatever the differences splitting “red” from “blue,” all Americans face a common, and evil, threat. That’s something both Kerry and Bush ought to remember.