Look, I'm not convinced the GOP is going to do everything possible to win the Senate back from Democrats because they don't know how to campaign effectively. But I think Larry Sabato might be off base on this:
A year ago, it was not hard to find Republican leaders who privately believed the party could score a dramatic breakthrough in the Senate, with the GOP emerging with perhaps 55 or 56 seats. This objective was vital not just for the jousting during President Obama’s final two years in the White House. At least as important is the fact that the GOP sees a much less friendly Senate map in 2016, when it will have to defend 24 of 34 seats, including incumbents elected in 2010 in Democratic states such as Illinois, Pennsylvania and Wisconsin.
I don't know that the GOP was thinking 55-56 seats in 2014 other than beyond wishing. While Larry Sabato is a quality prognosticator and interpreter of polling data, this seems a little more of political commentary in nature.
I for one do not buy the premise. That makes buying the conclusion impossible.