I’d add a few more details to Ramesh’s post about the context for Trump’s claim of fierce opposition to the war in Iraq – some context for the context, as it were.
In 1998, President Bill Clinton signed the Iraq Liberation Act, which had been overwhelmingly approved in both houses of Congress. It thus became the unambiguous foreign policy of the United States “to support efforts to remove the regime headed by Saddam Hussein from power in Iraq.” There was not much debate about the legislation, but there was a great deal of rhetoric about its having been a mistake in judgment for President George H.W. Bush to have failed to march on Baghdad and oust Saddam back in 1991. About six weeks after the bill was signed (and about three days before articles of impeachment against him were voted by the House), President Clinton commenced a four-day bombing campaign against Saddam’s regime in Iraq (Operation Desert Fox).
The point here is that if Trump really was standing against the weight of popular opinion urging that the removal of Saddam would be a major blunder that would destabilize the region, there was a great deal of opportunity for five years to fill the public record with that assessment. I don’t know of any such unequivocal public pronouncements prior to the March 2003 invasion. The clip from Trump’s January 28, 2003, Fox interview (by Neil Cavuto) is hardly an unequivocal argument against the war: it is more consistent with someone impatient for President George W. Bush either to proceed with the invasion or stand down – Trump took no solid position either way.
Finally, as I have pointed out before, in the September 11, 2002, interview with Howard Stern, besides tepidly replying, “Yeah, I guess so,” when the host asked if he was in favor of invading Iraq, Trump also elaborated, “I wish the first time it was done correctly.” Obviously, this was a reference to Bush-41’s decision not to invade Baghdad and overthrow Saddam’s regime eleven years earlier. That is a peculiar statement to have made if Trump’s belief was that removing Saddam would be a blunder that would destabilize the region.
To be clear, I believe (as I explain here and here) that, in light of Hillary Clinton’s own wavering on Iraq, none of this will mean much to voters – it is another in a long line of issues that makes this election more about whom one decides to vote against. Personally, and allowing that I am biased in this regard, I think Hillary’s false denial that she had described TPP as the “gold standard” of trade deals is a bigger deal because it is more current and relates to an issue – trade – that has taken on more importance in this election.