Democratic presidential hopeful Amy Klobuchar ended her bid for the White House on Monday.
The moderate candidate told her supporters to instead vote for former Vice President Joe Biden, and was set to head out to join him that evening.
She made the announcement one day before "Super Tuesday," when 14 states along with American Samoa and Democrats abroad will vote in a mixture of primaries and caucuses.
After performing poorly in Iowa and Nevada, Biden won the South Carolina primary last week. He is hoping to perform well on Tuesday, while the other perceived front-runner, Bernie Sanders, is also hoping to pick up votes from Klobuchar's supporters.
Klobuchar will fly to Dallas on Monday evening to join Biden at a rally.
The race narrows
Pete Buttigieg, a moderate like Klobuchar, pulled out of the race on Sunday. He has also asked his supporters to rally round Biden, according to a news agency.
Klobuchar's withdrawal came as a surprise given she was set to fare well in her home state of Minnesota on Tuesday.
Neither Sanders nor Biden have named running mates yet. The position could be doubly valuable given their advanced ages, making it possible they don't seek a second term as president.
The only other main candidates who remain in the race are progressive Elizabeth Warren and billionaire Mike Bloomberg.