Organized labor dominates the ranks of newspaper publishing like no other industry, except for perhaps Detroit’s automakers. And like the car companies, newspaper managers’ hands are tied when it comes to cutting salaries and right-sizing staffs, as union contracts negotiated in flush times remain in place. Lately, some newspapers have started to play hardball with unions — the San Francisco Chronicle (Hearst), the Seattle Times (independent) and Newark Star Ledger (Advance Publications) have all gained concessions from their unions. But some chains will have more concessions to extract than others. Below, the size of the union membership at a handful of chains, drawn from SEC filings.