Never denied Saddam was a "bad guy"
Only W and Co acted on poor and already discredited - by them own selves - intelligence to mislead Congress and the American People in order to justify the war they wanted.
It was not necessary to lie to the American People.
If the only way to depose Saddam was to invade and occupy Iraq, then make your case to the public and Congress, be honest about the reasons, the goals and the costs.
All the costs, including the above list, the tax increases needed to pay for it, and the need for their children and grandchildren to maintain the occupation for however many generations it takes to shove our way of life down the throats of a people who do not understand it and in fact despise it.
They knew that would go nowhere, so they used the fear of 9/11 and lied about the rest. "Quick little war", "Minimal Casualties", "We'll be greeted as liberators and heroes", " the Iraqi people are starving for democracy", etc...
Johnson backed into a war he didn't want, but they were honest about why.
They were honest about Korea, and we are still there
WW2 was obvious, and mostly everyone knew why they were making the sacrifices
W "The Decider" and Co lied to Congress and the people.
The public suppoerted the War On Terror, as in AQ and the Taliban, and those who support them. W turned his back on that war to pursue the NeoCons' puppet-gone-rogue of the day, and he lied about what we were doing, and why, and what the costs were. Cheney did because in 1994 he gaved an interview that predicted with amazing accuracy how it would go down. If he shared that knwledge with the rest of the Admin is unknown.