As of today, it has been two weeks since Joe Biden's disastrous debate performance that set off alarm bells for most of the Democratic Party as to whether he can be its candidate in November's presidential election.

Initially, many prominent figures within the party stood their ground. Now, they're falling like dominoes.

The first Democratic senator—Vermont's Peter Welch—has called for Biden to step aside, publicly declaring why in an op-ed for The Washington Post. Another—Connecticut's Richard Blumenthal—is making noises in that direction, while two others—Montana's Jon Tester and Ohio's Sherrod Brown—reportedly raised concerns at a lunch for Democratic senators.