If there's one rule in election-year politics, it's this: Don't mess with the science crowd. OK, labor unions and the NRA matter too, but John McCain may want to brush up on his stars and planets after Tuesday night's debate.

In the debate, McCain portrayed Barack Obama as an excessive spender, and he punctuated his attack (twice) with this example:

"[Obama] voted for nearly a billion dollars in pork barrel earmark projects, including, by the way, $3 million for an overhead projector at a planetarium in Chicago, Illinois. My friends, do we need to spend that kind of money?"

Turns out, a lot of people think we do. This is no ordinary overhead projector from your 5th grade classroom. The blog Cosmic Variance sums it up:

"If you've ever had the pleasure of visiting the Adler Planetarium, you'd probably guess that the 'overhead projector' he's talking about is the spectacular 'Sky Theater' -- one of the most engrossing, gorgeous venues for displaying visuals about space."

The science community is notoriously tight-knit, especially when rallying to a cause, and boy are they are rallying to this one. Alan Boyle's Cosmic Log has a great summary of the uproar:

-"For McCain to use this as a political zinger is insulting..." (Bad Astronomy)

-"Planetariums are Bridges to the Future, and America would be a much better place if all the congressional earmarks went to projects like them." (The Perfect Silence)

-"The logo for Senator John McCain's campaign has a star in the middle. I wonder what his guide star is? It can't be the same one that ten million children have seen at the Adler Planetarium. Why should anyone want their star to dim?" (Discovery Space)

The Adler Planetarium even issued a statement, noting that the request, ironically, was not even funded:

"To clarify, the Adler Planetarium requested federal support -- which was not funded -- to replace the projector in its historic Sky Theater, the first planetarium theater in the Western Hemisphere.... To remain competitive and ensure national security, it is vital that we educate and inspire the next generation of explorers to pursue careers in science, technology, engineering and math."

Linking a planetarium to national security may be a bit of a stretch, but the point is clear: McCain probably shouldn't count on the "science vote" this year.