Amy Klobuchar, the Minnesota senator, has withdrawn from the Democratic presidential race and will endorse Joe Biden, giving the former US vice-president a significant boost on the eve of the critical Super Tuesday primaries.
Ms Klobuchar revealed the decision one day after Pete Buttigieg, the former mayor of South Bend, Indiana quit the race after a dismal performance in South Carolina.
A moderate who came third in New Hampshire after a strong debate appearance, Ms Klobuchar, 59, had come under pressure to quit because she had no path to winning the 1,991 delegates needed to clinch the nomination. She came fifth in Iowa, and won no delegates in Nevada and South Carolina due to low support from non-white voters.
Coming on the heels of Mr Buttigieg’s withdrawal, her decision to quit should help consolidate the moderate segment of the Democratic electorate, as Mr Biden tries to prevent Bernie Sanders, the socialist Vermont senator, from winning the nomination.
US media said Mr Buttigieg would endorse Mr Biden on Monday during a rally in Texas, which has the second-largest haul of Super Tuesday delegates up for grabs. Mr Biden has received a cascade of endorsements since his crushing victory over Mr Sanders in South Carolina, as the party establishment tries to help him stall the ultra-progressive senator.
Super Tuesday has now become a race between four candidates: the progressives, Mr Sanders and Elizabeth Warren, Massachusetts senator, and the moderates, Mr Biden and former New York City mayor Michael Bloomberg. The four will square off in states from California and Texas to Virginia and North Carolina, in the most important day of the race, when one-third of the total delegates available in the entire 2020 Democratic primary are awarded.
The flurry of last-minute withdrawals also puts a spotlight on Mr Bloomberg, who has spent several hundreds of millions of dollars of his own money on the 14 Super Tuesday contests.
Mr Bloomberg entered the race late last year amid signs that Mr Biden was doing badly in the polls, out of concern that Mr Sanders would win the nomination and a belief that the Vermont senator would lose to Donald Trump because of his far-left policies.
The rapid resurgence of Mr Biden has raised questions about whether he can win enough support from Democrats to have a shot at the nomination. Mr Bloomberg, a former Republican who was pummeled in his first presidential debate last month, has risen in many of the Super Tuesday states over the past two months.
It remained unclear whether Mr Bloomberg will maintain that support as Mr Biden strengthens. Mr Bloomberg’s campaign said he was not considering dropping out of the race.
One Democratic donor who backs Mr Biden and has been courted by the Bloomberg campaign, said the former mayor was under “overwhelming” pressure to quit before Super Tuesday.
“I think he’s getting close to dropping,” the donor said. “The question is will he wait till Tuesday or Wednesday and look like an idiot, or go today and look like a hero.”
Larry Sabato, a University of Virginia politics expert, said the real choice was between Mr Biden and Mr Sanders. “The potential of a Sanders nomination has frightened loads of senior Democrats into Biden’s arms. Most Democrats aren’t buying Bloomberg after his disastrous debate and Warren flopped badly in the first four contests,” he said.
The withdrawal of Ms Klobuchar and Mr Buttigieg came as establishment Democrats panicked that Mr Sanders would win the party’s nomination because too many other contenders were splitting up the support of moderate voters.
Mr Biden performed badly in Iowa and even worse in New Hampshire, raising concern among his supporters about whether he could build a campaign to beat Mr Trump. He argued that he would do well in South Carolina, where 60 per cent of the Democratic electorate is African-American, and show he could create a winning coalition of voters.
On Saturday, Mr Biden did just that with a crushing victory over Mr Sanders and the rest of the field. The result has reinvigorated his campaign, which at one point was almost out of money.
With the exception of her home state, Ms Klobuchar was not doing well enough in any of the Super Tuesday states to win delegates. While her endorsement could help boost Mr Biden in Minnesota, it was possible that it could do more to help Mr Sanders, who was running just slightly behind Ms Klobuchar in the Minnesota polls.
“This is a big win for Bernie, who may win all of Minnesota’s delegates,” said Larry Jacobs, a University of Minnesota politics expert, who noted that delegates who fail to get 15 per cent of the vote in Minnesota will receive none of the state’s delegates.
Follow Demetri Sevastopulo on Twitter: @dimi