Wherever a Washington reporter travels these days, there is invariably a discussion about the reaction of the Washington press corps to the Reagan administration and the new, more Republican Congress. Often, the operative question is: Are you guys (the press) going to give them (the Republicans) a chance?

The question reflects the public perception of a sizable gab between the voters who choose a government and the reporters who cover it. The reality of that gap is confirmed by a new Brookings Institution book, "The Washington Reporters," by my old friend and sometimes colleague, Stephen Hess.

In 1978, Hess surveyed a cross-section of 476 Washington journalists making up almost two-fifths of those covering the national government for American commercial news organizations. The results demonstrate convincingly that the press corps in this city is no reflection demographically of the country to which it is reporting.

We are younger, whiter, more male and far better educated than the people for whom we write and broadcast. The largest bloc of reporters, three of eight, are in their 30s; only one in six suffers, as I do, from the post-50 blahs. More than 96 percent are white; almost 80 percent are males.

We are vastly overeducated -- 98.3 percent have some college training, almost half of some graduate training and one-third have graduate degrees, with most of the formal training outside the field of journalism in humanities or liberal arts.

The Northeast is overrepresented and Ronald Reagan's West greatly underrepresented, being the home of less than one in 10 Washington reporters.

Hess was too polite to ask, but I'm sure we were skewed another way -- being better paid than most of those in our audiences, even though a surprising lot of us drift out of reporting into other, presumably better-paying, work after age 40.

What most concerns people about the Washington press corps -- its possible political prejudice -- is not a point on which Hess chooses to be definitive. He made no independent effort to define or categorize the beliefs of his subjects, but he did ask the reporters themselves if they "feel there is a political bias in the Washington press corps."

Only a small fraction of his sample answered the question, and they split down the middle -- 51 to 49 percent -- in their yes-and-no answers. Of those who did think there was a bias, however, 96 percent said it was a bias, however, 96 percent said it was in the liberal direction.

On the other hand, only 42 percent of the whole group classified their own views as liberal (compared with 39 percent middle-of-the-road and 19 percent conservative) and 47 percent claimed to be more conservative than their perception of the press corps as a whole.

My own view, for what it is worth, is that there is about as much ideology in the average Washington reporter as there is vermouth in a good martini. Not much. At this moment in history, most of us citizens are hoping that Ronald Reagan and the Republicans can slay the dragon of inflation. It is wracking our budget on everything from cars to college tuitions as much as it is yours.

But whatever we hope as citizens, our professional attitude as journalists toward any set of politicians -- including the ones now governing here -- has to be one of skepticism. It's our job, as Hess understands, to poke behind the rhetoric of presidential pronouncements and examine the evidence that supports the claims for the particular elixir this goverment is peddling.

Hess faults us -- and rightly, I think -- for relying too much on interviews and too little on documented evidence, for chasing too many spot stories and spending too little time examining long-term trends.

His book is a reminder to those of us in the business that with the increasing editorial freedom and journalistic autonomy we have gained in our reporting jobs, we have a commensurate burden of responsibility. And, whether or not it's a consolation to the readers, it suggests that there are shortcomings in the Washington press corps that are more serious than our widely assumed but dubious political bias.