Which of the three is the most conservative: Giuliani, Romney, or Huckabee?

I suspect that Rudy Giuliani is because the liberal media seems to be doing everything possible to prevent him from receiving the Republican nomination. They seldom ever mention the fact that he sent members of the mafia to prison when he worked as a federal prosecutor in New York. Which of the three do you believe will be less likely to increase the amount of federal income taxes that you pay each year?