The Democratic Party faced a brewing crisis Friday as a wide range of lawmakers, party officials and activists began to actively consider what had previously been a pipe dream for pundits and worried voters: the prospect of replacing President Joe Biden on the ticket roughly four months before Election Day.

For two years, leading Democrats limited their concerns about Biden’s performance and age to private meetings and off-the-record conversations, leery of undermining an incumbent president in a rematch against former President Donald Trump.

But with Biden’s debate performance Thursday — uneven and at times incoherent, halting even on politically advantageous subjects such as abortion rights — that conversation has exploded into the public domain.