US election 2012: Newt Gingrich under renewed pressure to drop out Mr Gingrich stubbornly pledged to fight on until August's party convention in Florida. However, a senior adviser to his campaign told The Huffington Post that he and Mr Santorum "would make a powerful team against Barack Obama," hinting that a deal for him to step aside could be struck. Friends of Sheldon Adelson, the billionaire casino tycoon from Las Vegas who has bankrolled Winning Our Future, the 'Super PAC' campaigning for Mr Gingrich, with millions of dollars, were quoted as telling US media that he had "written his last cheque." Mr Romney, who finished a close third in the South and won caucuses in Hawaii and American Samoa, actually emerged from the night with 41 new delegates to the party convention, compared to 35 for Mr Santorum and 24 for Mr Gingrich. Ron Paul, a Texas congressman, finished a distant fourth. With their candidate now holding 494 delegates to Mr Santorum's 251 and Mr Gingrich's 131, Romney aides claimed his rivals had merely "moved closer to their date of mathematical elimination." After he won six states on Super Tuesday last week, they said an "Act of God" was needed for anyone else to win. The race for the nomination passed its halfway point with Tuesday's primaries. A loss to Mr Santorum there would revive severe concerns about Mr Romney's campaign. Mr Romney's failure to win over the party "base" however in two of America's most conservative states will add to mounting concerns that he would be incapable of rallying enough enthusiasm to beat Mr Obama in November's general election. Allies of Mr Santorum concede that it is unlikely he can reach the 1,144 delegates required to win the contest outright before August, and that his best hope lies in blocking Mr Romney from doing the same, creating a "contested" convention. However, Mr Appell said: "Santorum still has a chance of reaching the magic number. He could get on a roll and prove that Romney's support isn't as solid as assumed. And if he makes it to the convention, all bets are off.