The unsolicited, non-binding proposal is for $80 per share in cash from Clearlake, which is a current shareholder in the nonprofit software company. With 53,625,440 shares listed as outstanding as of December 31, that places the value of Blackbaud at $4.29 billion. Clearlake, which owns 9,751,837 shares, , would be paying about $3.52 billion for the shares it does not own. The investment group wrote in a letter to the Blackbaud board on April 14  that it believes, "The Company’s challenges have not been, and we believe cannot be, addressed as a public company.”  Clearlake said the company’s stock price “has materially underperformed compared to the NASDAQ Composite and Bessemer Emerging Cloud indices.” The letter, part of documents filed with the SEC,  did not spell out the challenges that Clearlake believes exist. Clearlake concluded if the Blackbaud board decides “a sale to Clearlake is not in the best interest of stockholders, we would support an alternative sale transaction recommended by the Board that provides superior stockholder value.”