Calvin gets upset because he needs his state I.D. card to go vote, but he dropped it in the park when police officers harassed him. However, California and most U.S. states do not have a Voter I.D. law that requires citizens to present valid I.D. before voting, so Calvin really didn't need it.
After Calvin finds his I.D. card, he rushes off to cast his vote, but the polling station is closed and locked. Calvin misses out because he came after voting hours were finished. However, it's broad daylight outside, and election stations always stay open late, until after dark, to allow citizens sufficient time to vote.