Selected parts of the latest email from the RNC:
The eight most recent public polls show the President's job approval is rising while approval of Congress is plummeting. The four polls that measured job approval for both the President and Congress show the President's ratings are higher.
The email provides this link (PDF) to supporting polling data.
The RNC's own data show that in 2 of the 8 most recent opinion polls, Bush's approval rating is decreasing (ARG and ABC/Wash. Post). So it seems rather silly to lie about the results.