It’s conventional wisdom now that this may be one of the nastiest presidential campaigns ever. But those keeping score should observe that, right now, the muddy epithets thrown at President Bush outweigh those thrown at Democrats by tons.

[IMGCAP(1)]That’s not the way things are being reported, though. The media seem to be uncritically accepting the Democratic charge that any criticism of Sen. John Kerry’s (Mass.) public record is “sliming” or “smearing.”

But for months now, Democrats have accused Bush of being a “liar” who “misled” or “deceived” the nation into the Iraq war; a “usurper” who “stole” the 2000 election in Florida; “a right-wing extremist” on tax, social and foreign policy; and a “menace to the nation’s basic liberties,” owing to his employment of Attorney General John Ashcroft.

Former Vice President Al Gore said Bush had “betrayed” the country in Iraq. No major Democrat said afterward that Gore had gone too far.

Democrats claim that Republicans either have questioned or will question their patriotism in this campaign, but actually the only accusations of lacking patriotism have come from Democrats.

Sen. Bob Graham (Fla.), when he was a candidate, said that Bush’s Iraq policy was “anti-patriotic at the core.” Last September, Kerry said that Bush “lives out a creed of greed for he and his friends” and that it was “unpatriotic” for Bush’s “friends” (i.e., corporate executives) to move jobs offshore. It was a regular staple of retired Gen. Wesley Clark’s campaign to say that Bush’s policies were “not patriotic.”

Howard Dean, when he was a candidate, charged that Ashcroft “is no patriot. He’s a direct descendant of Joseph McCarthy.”

After all of the Democratic attacks, I think Bush and his campaign should start devoting their energy and advertising dollars mostly to explaining his policies and re-educating Americans about basic economics and what it takes to create jobs.

When an incumbent president is up for re-election, the contest traditionally is a referendum on his performance and prospects. And, right now, many polls put Bush’s public approval rating at the lowest point in his presidency.

On the other hand, the Bush campaign has every right to raise doubts about Kerry’s record and programs, including on defense issues. And the media ought to cry foul when the Kerry campaign tries to put such discussion off limits.

Kerry spokeswoman Stephanie Cutter, for instance, said about criticism of Kerry’s defense record: “These attacks and smears against us are just one more example of the fundamental need to change the direction of the nation from Bush’s extreme agenda.”

Kerry said in mid-February that “given the record of this administration and their stunning lack of vision, the Republican attack machine may well have no choice but to resort to smear and fear.”

In a public letter to Bush last Saturday, Kerry implied that Bush was questioning his Vietnam service and said “it has been hard to believe that you would choose to reopen these wounds for your personal political gain.”

In fact, the Bush campaign and the GOP have acknowledged time and again that Kerry was a war hero and is due honor for his service, but that his record on defense and foreign policy is open to criticism.

Indeed, it is. Kerry is on record as opposing the MX missile, the B-1 bomber, the Tomahawk missile, the Apache helicopter, the Patriot missile, the Harrier jet and the F-15 fighter aircraft and has called for deep cuts in the intelligence budget.

After Republican National Committee Chairman Ed Gillespie recited that list in a press conference last week, Kerry’s campaign manager, Mary Beth Cahill, sent out an e-mail charging that “today, RNC chair Ed Gillespie made another desperate attack on the patriotism of John Kerry.” It was no such thing.

Defending Kerry more substantively, Rep. Norm Dicks (D-Wash.) and former Sen. Max Cleland (D-Ga.) claimed that Republicans were unfairly accusing Kerry of opposing such weapons systems because he voted against one Defense appropriations bill in 1991, at the end of the Cold War.

But as one of his own campaign press releases shows, Kerry favored all those cuts in 1984, long before the Cold War was over. He also supported a nuclear freeze that would have left the Soviet Union with a missile advantage in Europe.

And, in September 1995, Kerry introduced a deficit-reduction bill calling for the phasing-out of two Army divisions over a five-year period, cancellation of the Army’s tank-upgrade program and five years of $300 million reductions in the intelligence budget.

Kerry has claimed that the Bush campaign’s upcoming advertising campaign is code-named “Operation Carpet Bombing” and has charged this is somehow a slur on his Vietnam service.

In the first place, Bush ad guru Mark McKinnon denies ever hearing that term. In the second, the Bush campaign estimates that of the $6.7 million Kerry has spent on advertising during the primaries, 73 percent has been devoted to attacking Bush. Certainly, Kerry hasn’t attacked other Democrats and they haven’t attacked him, either.

Back in September, when I wrote a column lamenting that this could be the “nastiest” campaign ever, I anticipated that Republicans would help make it so by repeating their 2002 tactics against Cleland, who basically was accused in an ad of aiding Saddam Hussein and Osama bin Laden by voting against Bush’s Homeland Security Department.

This hasn’t happened — at least, not yet. Education Secretary Rod Paige referred to the National Education Association as a “terrorist organization” — clearly it was hyperbole, not a real accusation — and was carpet-bombed into an abject apology.

Besides that, no Republican of any stature has yet thrown what could even remotely be described as a low blow. If that changes, I’ll scream. But so far, if anyone’s “sliming,” it’s Democrats. And the media should call them on it.