MR. PRESIDENT: It's time you stop using Air Force One as your private limo. Even the limos you ride in are not your limos, they belong to the taxpayers of the United States for the use of the president. Today, you spent $1,600,000 of our tax dollars to fly to Las Vegas to give a speech that even your supporters asked you not to do in case you kill the immigration proposal made by eight senators yesterday. You could have spoken from the Oval Office without spending a dime or gallon of gas. According to the London Daily Mail, you …