The relative success of Trutherism has peaked and is now on the decline. Its genesis lies in right-wing populist conspiracism that was repackaged post-9/11 to appeal to left-of-centre consumers who felt traumatised and disenfranchised as a result of GOP dominance of US politics to 2006. An explanation of 9/11 as a plot masterminded by Bush or his associates appealed to some on the left, as another example of the illegitimacy of the Bush Administration and an example of their evil.
One of the greatest blows to the Troof Movement was when the Democratic Party took Congress in the 2006 Mid-terms. It destroyed the notion of "BushCo" as an all-powerful clique that controlled space-time, controlled all media, and could steal any elections it wanted. As Katrina, Iraq, and Afghanistan have unfolded, the capability of the Bush Administration to orchestrate the greatest deception of all time has been severely dented.
Since 2006, Trooferism is returning to the right-wing populism from which it was originally-derived. Trooferism's love affair with Ron Paul(1) is rather indicative of this, as well as Trooferism's bolder assertions that the Democratic Party was also "in on it". On the progressive messageboard DemocraticUnderground, resident Troofers are becoming bolder in smearing leading Democrats such as Bill Clinton and John Kerry.
Trooferism is losing its new consumers on the left, but it has gained converts to its anti-Semitic narratives in the process. The use of sources by the Troof Movement which are derived from the far-right has been one of the greater perpetrators. Increasingly, far-right anti-Semitic hate sites are using pseudo-left language to fool consumers into believing that they are on the Left.(2) Many Troofers do not see themselves as anti-Semitic but unfortunately cannot discern appropriate sources of information, much to the boon of hate groups.
The stain left by 9/11 Troof has been to the detriment of the Left in the United States. Right-wing hacks such as Bill O'Reilly have been happy to equate Trutherism with the "far left" and the Democratic Party as a whole. It has been rather fortunate for the Democratic Party that the propaganda benefits to the Right of equating 9/11 Troof with Democrats and progressives have been much lessened, and the potential embarrassment factor has been nullified.
Trooferism is in absolute decline. Its inability to gain key professionals to its cause and its penchant for isolating itself by name-calling many key thinkers on the Left(3) has lost any credibility on the Left it had.
If the Democratic Party can keep its momentum going to capture the White House in 2009, I fully expect Trooferism to give up any pseudo-left pretensions it holds if it has not already. Trooferism cannot thrive amongst Democrats when the Democratic Party is in government.
(1) Alex Jones' is a notable supporter of Ron Paul. Paul is also popular amongst many on the white supremacist StormFront website.
(2) WhatReallyHappened, Rense, IHR, Progressive Independent are four notable examples
(3) For example, British socialist environmentalist activist George Monbiot, and American academic Noam Chomksy were both subject to threats, name-calling, and slander as a result of publicly rejecting 9/11 Troof.
There is a lot of correlation between Twoofers, 'Big Pharma' woos, altie medicine proponents, UFO woo, 'global warming is a hoax' proponency, and other anti-science nuttery. Not every Twoofer will agree with every conspiracy theory mentioned above, but many do believe in some, most, if not all.
Like you I do see a distinct difference between LIHOPers and MIHOPers. Some LIHOPers do use conspiracist narratives but find MIHOP to be just to implausible, whilst other LIHOPers are just expressing feelings of disenfranchisement at a political situation which until November 2006 heavily marginalised the centre and left in the USA.
9/11 twoof is also in a tradition of anti-intellectualism and the distrust of scientific "élites" who supposedly suppress "twoof", twoof being the quackery, propaganda and pseudoscience which the woo believes in.
You are correct to point out that many right-wing populists opposed the Iraq War. The principles in play were isolationism rather than humanistic doubts, or in the case of Ron Paul, who opposed the Iraq War out of its expense and that it held no economic benefit. Others were 'ultra-patriots' who believed the USA was "duped" into "doing Israel's bidding", bringing up old anti-Semitic clichés of "AIPAC-controlled America" and "Z.O.G."