In the latest twist of Mr Trump's controversial campaign, the billionaire this week took the opportunity at an Arkansas rally to downplay the significance of the litigation against Trump University and call into question the integrity of the judge presiding over the case. When rival Marco Rubio drew attention to the class-action lawsuit, Mr Trump dismissed the case as a 'small deal' and argued that the judge presiding over the case had been 'very hostile' towards him, drawing particular attention to the judge's Latino heritage.

'I believe he happens to be Spanish, which is fine. He's Hispanic, which is fine,' Mr Trump said. In a later interview on Fox, Mr Trump took his comments further to suggest that the California judge's hostility towards Mr Trump may be connected to his policies on the Mexico-US border. 'I think it has to do with, perhaps, because I'm very, very strong on the border,' he said, reiterating again that the judge was 'Hispanic'. As part of his presidential campaign platform, Mr Trump has promised to build a wall between Mexico and the US to prevent border crossings by migrants.

Students defrauded

The class action against Trump University was brought in 2013 by New York Attorney General Eric Schneiderman on behalf of students who borrowed money to attend an 'elite' package of seminars. According to Mr Rubio, students borrowed as much as $36,000 for little more than 'a picture with a cardboard cutout of Donald Trump.' Mr Schneiderman has labeled Mr Trump's comments about the California judge as 'racial demagoguery' against a respected member of the judiciary. 'The State Supreme Court has already ruled that Trump University operated illegally in New York as an unlicensed educational institution, and we look forward to prevailing on the rest of our claims as the legal process moves forwards,' read a statement from Mr Schneiderman. Sources: CBS News; CBS News (2); Politico