Bush will not quit because he has not yet achieved his objective in Iraq.
His objective all along has been to capture the Iraqi oil for Exxon-Mobil and British Petroleum.
That is the purpose of the proposed Iraq Oil Law.
As long as there is any possibility of enacting that law, Bush will continue the killing and maiming and destruction of this war.
Lugar is only a very old and super-cautious politician trying to save the Republican Party. His speech is a lot of hot air that Bush can safely ignore.
The only thing that might make Bush listen would be threat of impeachment and removal from office by two thirds vote in the Senate.
The process has to start in the House of Representatives. The key person is a Democrat, Speaker Nancy Pelosi. She has stated clearly the impeachment of Bush and Cheney "is not on the table."
That's all. No threat of impeachment and removal from office and Lugar and all the other Republicans can blow all the hot air they want. Bush will ignore them and if necessary will have Rove slime them.