President Joe Biden has shed his reluctance to alter Senate rules on the filibuster as his political standing has diminished and his legislative agenda has stalled.

Biden began to move away from his support for the 60-vote threshold to end debate on most legislation this fall after insisting that abolishing the filibuster would lead to “chaos” as recently as July. But the intensity with which he has advocated changing the rules of a congressional chamber in which he served for 36 years has increased in the new year.