(AP) — President Joe Biden is marking the loss of 500,000 American lives to COVID-19. He’s offering an opportunity for national grief and catharsis Monday evening as he delicately balances the gravity of the moment with cautious expressions of hope. In stark contrast to his predecessor, Biden will offer a head-on acknowledgement of a grim pandemic milestone. The bleak threshold is being crossed against the contradictory backdrop of a drop in cases alongside fears about more contagious variants of the virus.