Labor unions wade into 2020 race with caution after being burned in 2016
WASHINGTON - As Democratic presidential candidates compete for coveted labor union endorsements that can bring an infusion of campaign resources and manpower, they are not the only ones on edge.
Labor leaders are also anxious - eager not to renew the discontent that rippled through their memberships four years ago when unions started jumping into the Democratic primary.
An effort designed in the last election to galvanize the membership and make a show of force, instead became divisive in several big unions whose leaderships backed Hillary Clinton over the more aggressively
