Some of the largest and most influential trade unions in the country are calling out Democrats for boosting guest worker programs and open borders policies. North America's Building Trades Unions--an umbrella organization representing three million workers and 15 major unions, including the Laborers and Teamsters--sent outgoing Sen. Barbara Mikulski (D., Md.) a letter Thursday accusing her of selling out workers by importing foreigners to work for "Close to Slavery" wages. Mikulski pushed for increasing the number of temporary H2B visas that allow companies to bring guest workers to the United States to fill seasonal jobs. "We wanted to express to...