OpinionJournal pretty well nails it:

President Bush still polls extremely well on his handling of the war on terror, and Democrats are trying to define the debate in a way that keeps him from playing to his strengths. The polls also show that Mr. Bush scores well as a "leader," so Democrats are also trying to stop him from reinforcing that image.

But what is Mr. Bush supposed to do, stop being President? Incumbency clearly has its large (and sometimes unfair) advantages. Yet try as we might, we can't seem to recall similar outrage about Bill Clinton's use of incumbency when he was running for re-election--at least not outrage that got any media traction.

Where, for example, was the tut-tutting about the former President "exploiting" the Oklahoma City bombing by giving an election-year speech there in April 1996? We'd also take the current handwringing a bit more seriously if we heard any similar worries about John Kerry "exploiting" his service in Vietnam.

One of the oddest things about the hullabaloo over the Bush ads is that these are precisely the kind of campaign spots the self-appointed media referees always say they like: positive, and focused on the candidate's message and record, not on tearing down the other guy. Despite Mr. Kerry's crocodile tears about the Republican "attack machine" and "smear" campaign, neither the President nor any other high-ranking Republican has so far taken a serious jab at either Mr. Kerry's character or his record.

Yet in case they eventually do, Democrats are also busy trying to take that off the table. When Georgia Republican Saxby Chambliss recently talked about Mr. Kerry's Senate votes against most U.S. weapons systems, he was assailed for attacking Mr. Kerry's "patriotism." This is an extension of the Max Cleland-as-martyr myth, asserting that it was somehow unfair for Republicans to attack the former Georgia Senator and Vietnam vet in the 2002 elections for his vote against the Homeland Security department.

So the Bush campaign is being presented with something of a Catch-22: Any attempt to talk about the President's own record will be branded "exploitative," while any talk about Mr. Kerry's will be called an attack on his "patriotism." Our advice to Mr. Bush is to choose his message and ignore the whining.

As for Democrats, they'd be wise to get over the idea that Mr. Kerry's Vietnam biography will cover them on the defense issue. For most Americans, 9/11 was the defining event of a generation, and they'll want to hear a serious debate about which candidate has the best policies to keep them safer in the years ahead. The more Democrats complain about Mr. Bush running on national security, the more voters may suspect that Democrats don't have any serious anti-terror ideas of their own.