Those that label themselves "moderate" are actually liberals, so that changes the dynamics considerably. For instance, right now Hillary is calling herself a "moderate" as does Clinton. Right!
They can call themselves "moderate" but a moderate what?
The answer is they are moderate Socialists.
A lot of liberals do that, to try and make conservatives look like "extremists".
Chuck Schumer calls himself a moderate all the time. And we all know how leftist he is.
Well, I suspect that journalists completing a private survey are less inclined to be dishonest about their beliefs than liberal politicians who are democratically accountable. So the survey may be less skewed than you think.
The other factor to consider is that journalism is a for-profit enterprise, like any other. Senationalism sells. If that means to focus on the downside of the war in Iraq, that's what journalists will do. If, on the other hand, it means talking about Monica Lewinsky 24/7, they'll do that, too. So regardless of how many journalists actually voted for Clinton, they still gave big coverage to his scandals and helped make him ineffective (which, I'd say, is a good thing) for the last two years of his presidency.
I would also say that, on economic issues at least, Clinton was very much a moderate -- considerably to my left, to be sure, but then again, I'm a conservative. Other than his health care plan, he had no big liberal ideas. The minimum wage increase was modest compared to what the unions were requesting, and his domestic agenda hardly got more ambitious than the Family Medical Leave Act (overwhelmingly popular), expansion of the Earned Income Tax Credit (Reagan-approved), and the almost-irrelevant anti-gun laws (stupid as they were, also very popular). He rightly refused to sign on to the Kyoto Protocol, and indeed, Clinton was downright conservative on free trade, corporate mergers, the death penalty, the war on drugs, and arguably, depending on whether you think his motives were cynical or sincere, welfare reform.
Now I still voted against Clinton and thought he was too liberal. But compared to the general electorate, calling him a moderate makes some sense.
On abortion, of course, Clinton was a nutcase -- just like almost every other elected representative in his party, all indebted to the pro-abortion lobby. And at heart, I'm sure he was no moderate on gay rights either, even though his only concrete policy (the "don't ask don't tell" compromise on gays in the military) turned out that way. But we shouldn't confuse him with an across-the-board liberal like Jesse Jackson, Nancy Pelosi, or Ted Kennedy.