WASHINGTON (AP) — The largest firefighters union is preparing this week to endorse Joe Biden’s expected bid for the presidency. The former vice president is the most high profile Democratic contender who has not yet jumped in the crowded primary. He is expected to launch a campaign this week. Harold Schaitberger, general president of the International Association of Fire Fighters, says the union’s board is meeting this week to vote on an endorsement. They expect to formally announce the decision next week.