Given John McCain's ballistic temper, I pity the poor aide who drew the short straw and had to show him the latest in bad news.

By now, after everything the good senator has done to pamper his base and pander to independents -- and after having had a free ride for months to solidify his numbers among both -- he must be wondering what it takes.

The latest in depressing news for McCain, of course, was yesterday's Los Angeles Times/Bloomberg poll [1], which read very much like the latest Newsweek poll, which itself was ridiculed and dismissed by many among the punditry as an aberrant quantification.  

But I doubt they're ridiculing this morning, or that McCain's hopes of a mere aberration are still intact. To quote the source:

In a two-man race between the major-party candidates, registered voters chose Obama over McCain by 49% to 37% in the national poll, conducted Thursday through Monday.

On a four-man ballot that included independent candidate Ralph Nader and Libertarian Bob Barr, voters chose Obama over McCain by 48% to 33%.

Which was precisely what Newsweek's poll said in either case, given the margin of error.

Even worse for McCain is that the political reputations to which he's tethered just keep on sinking, and with no salvation in sight: George Bush's approval rating has hit yet a new all-time low of 23 percent, according to the LA Times/Bloomberg poll; and only 29 percent of voters admitted to having a "positive feeling" about the Republican Party.

The second set of numbers is especially grim for McCain in the long run -- which is to say, through October -- yet wouldn't be quite as grim if Barack Obama weren't exploiting the situation so artfully.

For Democrats, winnable contests are the ones in which they race to the center -- and that, of course, is exactly what Obama is doing, plus some. The Dems can tack to the left when all seems hopeless, but this is hardly one of those occasions.

When far or at least comfortably ahead, it is always asked of the Democratic presidential candidate: How can you screw this up?

The answer? Appeal to the base, long after the primaries are put away.

In fact, that's probably the only way Obama can now screw this up. But he's admirably refusing to buckle, and the base had best brace itself for more middle-to-right positioning to come.

Because in that positioning there's victory, and Republican strategists know it and fear it as well as Obama knows it and loves it.

Said, for instance, GOP media consultant Alex Castellanos to the Washington Post [2]: "[Obama] is not trying to cobble together the old Democratic coalition of interest groups and get 48 percent like John Kerry. This is not three yards and a cloud of dust. This is an aggressive leap across the 50-yard line to play on Republican turf."

Obama's advisers believe that independents will break decisively their way by fall, which likely would be decisive itself. "In the end," however, they also "believe that whichever candidate wins the highest percentage of voters in the other party is likely to be the next occupant of the White House."

And they're taking no chances. Obama is going right -- literally -- at the heart of the opposition, which may peeve the leftward base to no end, but is exceedingly smart.

One Obama confidant put it well: "People and commentators have been saying we know Barack is hopeful and that he appeals to a broad cross section of the public. But perhaps people didn't know how tough he is. He's been saying all along, don't confuse hope with naivete."

I might add that the base should not confuse strategy with idealistic intent.