The Arizona Tax Research Association, one of the more unlikely supporters of Brewer's sales tax proposal earlier this year, has withdrawn its backing of the measure. In a Sept. 22 letter to Brewer that was published in ATRA's latest newsletter, President Kevin McCarthy wrote that its support was contingent on the tax increase being used to cut the deficit, not pay for increased spending. McCarthy told our reporter that ATRA's board of directors was caught off guard by Brewer's vetoes last month. "It would be an understatement to say that my board was taken aback by that," he said. "We're not supporting any referral anymore until we're darn certain that any revenue increases are going to deficit reductions." (Go to the documents section on yellowsheetreport.com to see the letter.)