Even though Republicans controlled both House and Senate in Congress while the lawless Bush/Cheney administration chose to ILLEGALLY invade Iraq, a nation that had never once attacked the United States, some of those Republicans cannot be blamed for authorizing the use of force because they were lied to---Cheney and Bush had been plotting since only four days after taking office how to "come up with an excuse the public would buy" to invade oil-rich Iraq so that oilmen Cheney, GW, Rumsfeld, and Halliburton could get themselves a very lucrative foothold in the even-oil-richer Middle East (words of then-Treasury Secretary Paul O'Neill in "The Price of Loyalty"). When the repeated, and repeated again warnings (both written and oral) were ignored by the administration, one could reasonably assume that the pending attacks were Cheney's desired "excuse the public would buy" to sell Congress and the American people on the idea of an ILLEGAL lie-based invasion of a sleeping Iraq, turning the U.S. into a terrorist nation, unfortunately.
Interestingly, Cheney and Bush pressured then-Chairman of the NY/NJ Port Authority (and also former Chairman of the National Republican Finance Committee) Lewis M. Eisenberg only six weeks prior to the 9/11 attacks to award the coveted 99-year lease of the World Trade Center to two cronies (and, like Eisenberg, big $$ contributors to the Bush/Cheney campaigns and long-time friends of Rupert Murdoch) Larry Silverstein of Silverstein Properties and former Israeli Commando Frank Lowy of Wesfield Properties for the LOWEST BID ($3.2 billion---only a tiny fraction of what the lease was actually worth). Convenient, huh? Silverstein then sued for double indemnity (double payouts) because, as he told the court, "There were two planes."
At least two of the 13 insurers of the World Trade Center were controlled by Bush family members: Board Chairman and maternal uncle Wirt Walker I, maternal cousin Wirt Walker III, and GW's brother Marvin Bush, plus paternal uncle Jonathan Bush was CEO of the Texas-based insurer. These same Bush family four controlled the notorious Riggs Bank which was discovered to have laundered money for two of the 9/11 hijackers through the wife of Prince Bandar, a long-time friend to GW (see Michael Moore's documentary "Fahrenheit 9/11") and also a trained Saudi military pilot who was a loyal friend to the bin Laden family. Another "coincidence" re: 9/11 is that the firm contracted by the Bush/Cheney administration to provide "security" to the World Trade Center was SECURACOM (changed to SECURATEC, Inc. post-9/11), and also provide security for the Dulles International Airport from whence to 9/11 planes flew, and for United Airlines (two attack planes were United) had the same Bush family three (Wirt I, Wirt III, and brother Marvin) on their Board, Wirt I Chairman.
The evil of 9/11 runs deep, but Congressional Republicans and Democrats could not be blamed for being duped by ruthless hidden-agenda Cheney, Rumsfeld, Wolfowitz, GW, and all those no-bid contractors from the Carlyle Group (cited in "Fahrenheit 9/11") lined up to profiteer from the ILLEGAL invasion. I rarely defend Republicans, but on this one issue, had they known the truth that there were no WMDs and that Iraq had no involvement in 9/11 or even that the Washington D.C.-based rightwing PR firm Hill & Knowlton had been kept on retainer by the lawless Bush/Cheney administration (originally hired by the Reagan/Bush-Bush/Quayle administrations) to falsely paint Saddam as a "villain" in the minds of the American people to set up a Cheney-desired excuse for going to war in Iraq (shown on "60 Minutes" during the Gulf War, also lie-based), I like to believe that the Congressional Republicans would not have voted for the use of force in Iraq.