It is said that John McCain is no true conservative because he did not support Bush’s tax cuts. Remember, though, that economic conservatism used to mean cutting spending and balancing the budget. To this mindset, the government should not spend money it does not have, which sometimes means raising taxes. Those old school conservatives would consider the current practice of cutting taxes while also increasing spending to be LIBERAL.
McCain is that old school kind of an economic conservative, being a consistent budget-trimmer and opponent of pork-barrel earmarks. Whether his economic policies are good or bad is a separate question. But it’s not correct to say he isn’t conservative. It just depends on what kind of conservatism you are advocating.