Romney calls on rivals to quit race Mitt Romney's campaign has called on his Republican rivals to heed "the basic principles of math" and drop out of the 2012 nomination race before they irreparably damage the party's chances of beating Barack Obama in November. The former Massachusetts governor won six of the 10 states up for grabs on Super Tuesday, the biggest day of the Republican campaign so far, and is projected to have secured 415 of the 1,144 delegates needed to win the Republican nomination. Romney campaign officials on Wednesday maintained that his two main rivals, Rick Santorum and Newt Gingrich, would need "an act of God" to win enough delegates to take the nomination with the pair projected to have 176 and 105 respectively. For Mr Santorum to win the nomination, he must win 65 per cent of delegates in future primaries, while Mr Gingrich needs 70 per cent, the officials said. "As Governor Romney's opponents attempt to ignore the basic principles of math, the only person's odds of winning they are increasing are President Obama's," Rich Beeson, Mr Romney's political director, wrote in a memo distributed to reporters. "They would have to perform in ways they have so far not performed - there is simply no large chunk of delegates out there for them to get," said another Romney adviser. However, both Mr Santorum and Mr Gingrich used their own victory speeches on Tuesday night to justify their decisions to remain in the race with both promising to go all the way to the party's convention in August. The prolonged Republican race, in which the candidates and their surrogates have spent tens of millions of dollars on political advertisements attacking each other, has taken its toll on Mr Romney, and the party's, standing among independent voters who will decide the 2012 election. Senior Obama campaign officials were clearly encouraged at what they argued was the lack of enthusiasm for Mr Romney on Super Tuesday, and his trouble attracting working-class, young and independent voters. David Axelrod, Mr Obama's senior strategist, called it "super glue day" for the Romney campaign. "They are still stuck with Gingrich and Santorum and the prospect of a long race here," Mr Axelrod told reporters. Delegates are awarded by processes that vary from state to state, with most divided proportionately, or according to whichever candidates win the vote in a congressional district. Mr Romney's vastly superior campaign muscle gives him a big advantage, as Mr Santorum and Mr Gingrich have not been able to get either themselves or delegates running in their names on the ballot in key states. Mr Romney has been forced to spend money he had hoped to hoard for the general election beating back Mr Santorum and Mr Gingrich. But his campaign said he had raised $11.5m in February, the second best fundraising month so far, after December. Having struggled to gain traction in southern states, Mr Romney faces primaries in Alabama, Mississippi and Louisiana over the next three weeks. But the outcomes in other delegate-rich states, including Illinois, New York and Pennsylvania - Mr Santorum's home state - could help clinch the race by the end of April.