AP, Washington :Hillary Rodham Clinton was endorsed Saturday by the National Education Association, the nation’s largest labor union, giving her campaign a boost in an increasingly competitive Democratic primary race.With 3 million members, the NEA’s support will help Clinton in her primary bid against Vermont Sen. Bernie Sanders, who has galvanized liberal Democrats and announced this week he had raised nearly as much money as Clinton during the past three months.”We chose Hillary Clinton because she chose kids. She’s had kids in her heart from pre-school to graduate school,” said NEA president Lily Eskelsen Garcia in a phone interview. She said Clinton addressed the 175-member NEA board on Saturday for more than an hour, answering questions about testing, special education and college affordability.Many rank-and-file union members have backed Sanders and pressured labor leaders not to endorse Clinton with four months remaining before the first contests in Iowa and New Hampshire.Eskelsen Garcia said 75 percent of the union’s board supported Clinton and the union felt it could have more influence by endorsing during the primaries.