The strangest flirtation in Washington is the ongoing courtship between a subset of Republicans and the Teamsters union . It could also be among the most economically destructive. This May Day-November relationship is built around mutual neediness: Union membership is trending down. Only 6% of today’s private-sector workers belong to a labor union, down from 10% in the mid-1990s. Some DC Republicans, most notably Missouri Sen. Josh Hawley , reckon that if they tilt federal labor rules even