By Mark Willen, Senior Political Editor June 25, 2008 When a Newsweek poll last weekend showed Barack Obama leading John McCain by 15 points, twice the average of other polls, it seemed to be an aberration. But now another poll out today has the same result, suggesting McCain is in very serious trouble.The new Bloomberg/Los Angeles Times poll has Obama leading 48% to 33%, with third and fourth party candidates Ralph Nader and Bob Barr collecting 7% between them. The other 12% are undecided. Most other polls have shown the race closer, with heavy emphasis on the fact that independents are splitting almost evenly. The Bloomberg/Los Angeles Times poll shows that, too. In fact, McCain leads slightly among independents, 36% to 33%. Pundits put a lot of importance on that because in most elections, it is independents who decide the outcome. But it would be a big mistake for McCain to take much solace in that. Consider that four years ago voters described themselves as roughly one-third Democratic, one-third Republican and one-third independent. In the current Bloomberg/Los Angeles Times poll, that has shifted to 39% Democratic, 27% independent and only 22% Republican. In short, many who once described themselves as independents now identify with the Democrats and many Republicans now call themselves independent. So today's independent vote that is splitting roughly evenly includes a lot of former Republicans who would have been expected to be solidly in that camp. That's hardly a reason for McCain to feel comfortable. Advertisement In the Bloomberg/Los Angeles Times poll, Obama leads in several categories, but what is most striking is his 54-29 advantage among women (similar to the Newsweek poll). Since Hillary Clinton dropped out of the race, her supporters have gradually moved past their disappointment and now seem to be lining up firmly behind Obama. Another big advantage for Obama is enthusiasm. More than 80% of his backers say they're excited and certain to vote; only 45% of McCain's supporters say that. McCain still hasn't shored up the Republican base, but the more he tries to do that by embracing conservative positions and issues, the more he risks losing the center and tying himself to Bush, whose approval rating dropped to 23%. If McCain is looking for good news, he can take a bit of comfort in the fact that Obama is polling under 50%, a sign of vulnerability (although the Newsweek poll was 51-36). He also can note that respondents think he's more experienced and, by a 17-point margin, better able to handle terrorism. But they prefer Obama on the economy (49% to 28%) and other domestic issues (even taxes), which they view as much more important. Interestingly, McCain wins support for his call to do more offshore drilling, but it doesn't translate into votes. Respondents still say they'd rather that Obama be in charge of energy policy.