He may be a certified lame duck now, but President Bush and his truest believers are about to launch their final campaign - an eye-popping, half-billion-dollar drive for the Bush presidential library.

Eager to begin refurbishing his tattered legacy, the President hopes to raise $500 million to build his library and a think tank at Southern Methodist University in Dallas. Bush lived in Dallas until he was elected governor of Texas in 1995.

Bush sources with direct knowledge of library plans told the Daily News that SMU and Bush fund-raisers hope to get half of the half billion from what they call "megadonations" of $10 million to $20 million a pop.