President Trump on Thursday accused Democrats of trying to steal this week’s California primary elections and said the U.S. Attorney’s Office in Los Angeles would investigate the surge of late mail-in ballots and the slow vote count.The probe would focus on Tuesday’s jungle primaries for California governor and Los Angeles mayor, in which Republican candidates had a strong performance in early results.The final results may not be known for weeks because of a deluge of late-arriving mail-in ballots that officials say will take time to count, state officials warned.