After 25 state primary contests, Biden has opened up a nearly insurmountable lead by capturing 1,180 delegates on the road to the 1,191 needed to clinch the party nomination. Sanders has secured 885 delegates while Gabbard has won only two.
"Today I am suspending my presidential campaign and offering my full support to vice president Joe Biden in his quest to bring our country together," Gabbard said in a statement.
Her departure officially leaves the Democratic contest to a two-way race between Biden and Sanders, and Sanders has been taking stock of his campaign after Biden swept Florida, Illinois and Arizona Tuesday.
"After Tuesday’s election it’s clear that Democratic primary voters have chosen Vice President Joe Biden to be the person who will take on President Trump in the general election," Gabbard said.
The largest prizes remaining in the primary race include the states of New York, Pennsylvania, and New Jersey ahead of the party’s convention in Milwaukee, Wisconsin in July.
Earlier this month, another Democratic candidate Elizabeth Warren announced that she was ending her campaign but refrained from endorsing any of the remaining candidates, while Michael Bloomberg, Pete Buttigieg, and Amy Klobuchar withdrew from the race to endorse Biden for the presidential bid.