The State Board of Education may decide today to push back the arrival of new science textbooks to 2013. No, it’s not because the publishers dared to mention evolution. It’s because of the budget crunch. By delaying the arrival of books, the Legislature can pay part of the money in the 2011 budget, and party in the 2013 budget. The delay could affect the distribution of social studies textbooks, the standards for which have been so hotly debated in recent weeks. Social studies books are due to arrive in fall 2013 but may be have to be pushed back so that the Legislature can spread out the payments.