His `straight talk' campaign has spawned a groundswell of support for an insurgent White House race, but maverick presidential candidate John McCain's mouth is also getting him into trouble. The Arizona senator was in a too-close-to-call race with front-runner George W. Bush for the South Carolina primary that has become a must-win contest for the Republican nomination to run in the November 7 general elections. And he was on the defensive after using the term `gooks' when referring to the Vietnamese prison guards who held him captive for five years during the war.``I wouldn't have used that word,'' Bush told reporters at a campaign stop in Clinton. He refused to comment further, however, joking that he didn't want to be accused of making more of the nasty attacks that have characterised this race. McCain had used the anti-Asian slur last year, and when asked about it he defended his remarks and repeated the offending word twice. ``If anybody doesn't believe that these interrogators and these prison guards who tortured me and my friends were not cruel and sadistic people that deserve the appellation `gook' there's no appellation that could be bad enough,'' he said. ``I'm referring to our prison guards,'' he said. ``I will continue to refer to them probably in language that might offend some people here. I hated the gooks and will continue to hate them as long as I live.''The comments could compound complaints about McCain's stand on race. Both he and Bush have been criticised for failing to take a stand on protests against the Confederate flag that hangs over South Carolina's Capitol, viewed by some as a symbol for racism. McCain was also under fire for refusing a public interest group's request to sack a top campaign aide whose writings glorified slavery and vilified Black leaders. But disarming candour has won McCain support from the media and the public, who are enthralled by the momentum he launched after winning the first primary in New Hampshire on February 1. He dubbed his campaign bus `The Straight Talk Express' to underscore his unorthodox approach to politics and makes much of the constant access he gives reporters.However, frank talk has gotten him in trouble before and it could cause him to stumble in his bid to replace President Bill Clinton. Last year, McCain was forced to apologise for joking that the reason Chelsea Clinton was so plain was because she was the offspring of First Lady Hillary Clinton and Attorney General Janet Reno. McCain was not the only one on the campaign trail with a runaway mouth, however.At a Bush rally, US Representative J. C. Watts introduced the Texas Governor with an awkward attempt to counter concerns that the candidate is an intellectual lightweight. ``You don't have to be clever to be a good President, you can buy clever,'' he said. Watts was echoing remarks Bush made after he failed a pop quiz on foreign policy in which he argued that he didn't need to know everything if he employed the best advisors.