Klobuchar becomes the third Democrat to quit since the South Carolina primary ended on Saturday evening 

Minnesota senator will publicly endorse Joe Biden in Dallas tonight in boost to the former vice president

Pete Buttigieg, who quit Sunday, now says he will endorse Joe Biden too 

Announcement comes one day before voters in her home state of Minnesota were to go to the polls as part of the 14 states that vote on 'Super Tuesday'

Klobuchar looked poised to do well in Minnesota and Minnesota only

Tom Steyer, the billionaire who quit Saturday has yet to endorse anyone

14 states will vote Tuesday with 1,357 delegates, a third of the total up for grabs