Newspapers have also, at least until rather recently, demanded that their writers know a region. Not before they got hired, but once they started to work in it. Papers may have hired from diverse regional backgrounds (and newspapers draw from a more geographically and educationally diverse population of reporters than Rubin thinks they do), but what they demanded of their workers is that they become regional specialists. That's what running people through the Metro Desk was designed to do. Until fairly recently, to report on national politics, you had to get to know the problems of the city or of dense close-in suburbs first. You had to take a crash course in the culture of the city and the region in which your newspaper was based.

Also important: Because employment at these city-based newspapers is voluntary, they tend to attract reporters who want to live in cities. The New York Times, for example, gets the Iowans who want to leave Iowa and live in Manhattan or Brooklyn. It does not get as many job applicants who want to live in traditional rural communities, because it is not a rural-community-based employer. Newspapers hire people who can deal with working in cities -- big, major, complicated, diverse, progressive cities -- and who will obey the socially progressive laws of those cities at work, even if they live off in the 'burbs somewhere.

There are successful conservative newspapers in cities, but they are usually the scrappy local underdogs to the big mainstream dailies bought by the plurality of the regional paper-buying population. Think: The Boston Herald (conservative) versus The Boston Globe. The New York Post (conservative) versus the New York Times and Daily News. The Washington Times (conservative) versus the Washington Post.

Actually, let's look at this last example more closely, because the Washington market is suffering one of the sharpest newspaper contractions in the country, and it is the printed papers whose conservatism spills over the opinion wall into the news pages that have been having the toughest time of it in this Obama-friendly region. The Washington Times laid off more than 40 percent of its newsroom in 2009, then another 20 people in 2013, and is on track to contract again through another round of layoffs. The Washington Examiner, founded in 2005 with big ambitions and a right-leaning editorial page, just announced it's ceasing near-daily printing and becoming a single weekly magazine plus a website, replacing its original model of a local-news-covering paper with a regional distribution with the only form of media that's even harder to sustain as a business, the weekly newsmagazine (think of the fates of Newsweek, or U.S. News & World Report) with national ambitions. Eighty-seven people were laid off, and the new publication is slated to focus on "national politics" and "hire at least 20 new people," according to a Huffington Post report, dropping its readership of Metro riders looking for crime news in favor of a new audience of "roughly 45,000 professionals in government, public affairs, advocacy and academia."