With the '99 data the story is even worse for Mars, as favor for setting aside money for a Mars mission had climbed over 30 years to 43%. As you mention policy, this was likely attributable at least in part to the Mars Sojourner mission and the publication of Zubrin's "The Case for Mars". It can be inferred from this that perhaps the rise in support from 39% to 43% in favor of a manned Mars mission wasn't a sustained rise over that thirty years, but may have been a bump fueled by the Mars propaganda machine in full production mode in the last half of the 1990s.

From 43% it then dropped to 40% over the last six years. A fair decrease by any measure, and essentially where it was back in 1969 (39%).

When looking at the opposition, one sees it essentially flat over the first 30 years (from 53% in '69 to 54% in '99) while those with no opinion dropped from 8% to 3%.

So folks were more aware of the whole Mars thing by 1999, and whether the undecideds all moved into the favor column, or half to favor, half to opposed, and some of the opposed moved to favor, or what have you, there had been a clear shift between 1969 and 1999, and it seemed to be in favor of Mars.

Now, a mere six years on, support for Mars, even after the Arean rover blitz, is back down to where it was back in '69, while opposition has continued to grow, up to 58%, while those with no opinion continued to shrink, down to 2%.

The 75% decrease in those with no opinion since 1969 versus June of 2005 shows that in general there is greater awareness of Mars. This awareness is more positive in those under 50, and in men.

My take is that the Baby Boom generation has no intention of paying for a Marsprojekt (heck, they don't want to pay for much of anything :-). Their kids (X & Y) might be more favorably disposed, but working temp mcjobs doesn't really make them significant taxpayers (as compared with the majority of the Boomers), and policy makers in D.C. know this. They also know that women REALLY don't like these adventures abroad (68% oppose/29% favor), given the needs of the homestead, and as women continue to move into positions of overt power and authority this may serve counter to the interests of those interested in Mars.

(Mitigant: focus efforts on the constituencies of powerful women congresscritters. Detriment: sending Bob to go talk to Senator Hutchison ;-)

Even with the sloppy margins of error of the poll, and it does allow for a lot of ambiguity in the favor column, there's much less ambiguity in the opposed and no opinion columns, and the message there is that the more people are informed the more opposed they become, with more people opposed to a crewed Mars mission now than ever before.