Democrats are dropping out and backing Joe Biden. But he faces a tougher test on Super Tuesday.

Decisions by Amy Klobuchar and Pete Buttigieg to drop out and endorse Biden could consolidate his support among more centrist voters and those who fear Bernie Sanders is too liberal to beat Trump.

Democratic presidential candidate Joe Biden during a campaign rally at Texas Southern University in Houston on March 2, 2020.Read moreMichael Wyke / AP

by Jonathan Tamari and Julia Terruso

Updated March 3, 2020, 9:33 a.m. ET

Published March 2, 2020, 2:27 p.m. ET