From DKos' BarbinMD:
So, when did the Republican leadership learn about Arlen Specter's party switch? Apparently not until the last minute:
Senate Republican leaders said they had received no heads up from Sen. Arlen Specter (Pa.) about his decision to leave the Republican Party and run for re-election as a Democrat.
Specter told Senate Majority Leader Harry Reid (D-Nev.) late Monday that he would leave the ranks of the GOP to caucus with Democrats, giving them control of 59 Senate seats.
Republican leaders, however, said they were unaware of Specter’s decision as late as noontime Tuesday as they walked into an emergency meeting in Senate Republican Leader Mitch McConnell’s (R-Ky.) office. [...]
“It’s all just rumors now,” said Cornyn at noon.