I had always opposed the Iraq War because, as I argued at the time, the premise made no sense to me. The premise was that Saddam Hussein had chemical/biological/nuclear weapons, and that he would give these weapons to Al Qaeda to carry out attacks on the United States. But such a theory completely ignored who Saddam Hussein and Osama bin Laden were.
Saddam Hussein was a crafty, but ultimately, a run-of-the-mill strongman. He wanted to be powerful, and to maintain power. If maintaining power meant intimidating his people through torture, murder, and occasional genocide (as he did in the Kurdish north), so be it. If taking power meant invading neighbors, then he would do that too. He would even attack Israel if it could dismantle an alliance arrayed against him. But, he was no idealist, and that was why the U.S. backed Saddam in his early days of power.
By contrast, Osama bin Laden was an idealist. He grew up rich, but left his riches to fight in Afghanistan. He fought the Soviets for ten years, and then turned his attention to the United States. Where Saddam Hussein was flexible ideologically, Osama bin Laden was not. Moreover, bin Laden opposed the secularism of the Ba'athist movement, which Saddam Hussein was.
In other words, these two were not going to be on friendly terms. Ever. The idea that Saddam would entrust WMD to someone he wouldn't like, much less trust, was HIGHLY unlikely. Add to that concept that Saddam before had only entrusted these weapons to his first cousin ("Chemical Ali"), and even if Saddam had WMD, the odds that he would give these weapons to Al Qaeda were next to none. Of course, it turns out that Saddam did not have any WMD anyway.
At the time, though, no one was going to listen to someone like me. I was, after all, just a law student. But, in the aftermath, the interesting thing is that the Iraq War had some interesting effects on American politics and journalism.
On the political side, the Iraq War was responsible for Barack Obama's election. Not completely responsible, mind you, but it had a huge effect because his early opposition to the Iraq War solidified his position with the base. During the primary, Clinton couldn't outflank Obama to his left (always a fear during a Democratic primary) because Obama opposed the Iraq War, and Clinton did not. This opposition allowed Obama to take more conventional positions, while getting credit for being more liberal than he actually was.* This had to drive Hillary Clinton completely crazy.
What's more, the Iraq War gave us the first glimpse of how inept the Bush Administration really was. Soldiers were sent out to war so ill-equipped that the folks back home actually spent their own money to get their relatives body armor. Soldiers and Marines who were injured had to deal with substandard health care back home. And the Bush Administration put Iraq in the hands men like Paul Brenner, et al., who consistently made horrendously bad decisions (such as, dismantling the Iraqi Army, failing to protect weapons caches, trusting Chalabi, and many, many more).
This ineptitude lead to the losses the Republican Party faced in 2006, 2008, and 2012. The only real win on the national stage for the GOP came in 2010, when a fair number of Republicans distinguished themselves from the Republican Party elites.
On the journalism side, the Iraq War really accelerated the changes in the media that had already begun. Bloggers, who got the Iraq War right, became more influential. Still, and as Media Matters reminds us, a fair number of commentators who got the Iraq War wrong are still in positions of power (many of whom predicted a Romney landslide, btw). Nonetheless, the media is more diverse, more fragmented than it was in 2003, and that's a good thing.
With that said, I still believe the Iraq War was a horrendous error that will haunt America for at least a generation. Even though we "won" the war, it cost tens of thousands of lives, and trillions of dollars. Strategically, it allowed Al Qaeda to survive much longer than it should. It probably has lead to the survival of the Taliban in Afghanistan. And Iraq is more fragmented and potentially dangerous than it was before.**
*Republicans, and especially conservatives, love to talk about how Obama wasn't fully vetted by the time he was elected. From the conservative prospective, this is nonsense. The conservative media threw everything at Obama, its just that nothing stuck. If anyone should be pissed about vetting, it has to be Clinton, who had a fair number of positions to Obama's left, and had to play the role of the conservative/moderate Democrat because of her support for the Iraq War.
**With one exception - the Kurdish region in Northern Iraq, which has been stable and prosperous ever since the War. Hopefully, this area won't destabilize Turkey, which has its own Kurdish population.