Governor Andrew Cuomo sent a letter to the head of the state Board of Regents this afternoon (which is kind of quaintly interesting all by itself), describing how he wants to deal with one of the most volatile issues in education: evaluating public school teachers. Between the lines of the long, dense letter are some fascinating politics. The first bit of intrigue is that Cuomo seems to have coordinated the proposal with Mayor Michael Bloomberg, along with the leaders of the state’s four other large school districts. The second is that the governor goes nowhere near Bloomberg’s dream of ending “LIFO,” the state requirement that teachers be laid off strictly according to seniority, but he does hand the mayor a potentially significant bargaining chip. Cuomo says he wants to make student performance on standardized tests a larger part of the evaluation, an idea the teachers’ unions have always resisted. Cuomo can’t impose the new evaluation process unilaterally without risking a court fight; it needs to be agreed upon through collective bargaining. The city’s teachers union, the UFT, has been without a contract since 2009. Bloomberg is currently threatening to lay off roughly 5,000 UFT members. So Cuomo may have just given the mayor more leverage to cut a new contract deal: If the UFT accepts the governor’s tougher evaluation standards, perhaps Bloomberg could find a way to reduce the teacher layoffs a little.