The impressionistic and poetic style of the second half of If Beale Street Could Talk is undermined by a trite and sentimental first act. A man is wrongfully convicted of a crime, his girlfriend figures out she's pregnant while he is in jail, and then her caricature of an overbearing and religious mother-in-law gets upset in a sequence with such unconvincing performances that they were impossible to take seriously.
The film is at its best when it leans into a…