Donald Trump and Ben Carson say they will boycott if CNBC extends the length of the debate.\r<br>\r<br>Republican presidential candidates Donald Trump and Ben Carson have threatened to boycott the next primary debate if CNBC does not adhere to their .\r<br>\r<br>GOP Presidential Candidates Threaten to Boycott Next Debate The race for president, lots of action on the campaign trail as Donald Trump and Ben Carson .\r<br>\r<br>Donald Trump and Ben Carson say they will boycott if CNBC extends the length of the debate. Republican presidential candidates Donald Trump and Ben .
